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HomeMy WebLinkAbout2019-09-17 Response Comments SPR The M6rin-Cameron l August 13, 2019 North Andover Planning Board C/o Eitan Goldberg, Chair Town of North Andover 130 Main Street North Andover, MA 01845 RE: Response to Comments Application for Site Plan Approval 505 Sutton Street/Sutton Street Redevelopment, LLC On behalf of the owner, Sutton Street Redevelopment, LLC (Applicant), The Morin-Cameron Group, Inc. (MCG) has provided the following responses to the TEC Company peer review comments issued on August 12, 2019. The Peer Review comments are listed below in italics, with MCG's response following. Included with this submission are the following: - "Multifamily Site Development Plans in North Andover, Massachusetts 505 Sutton Street" by The Morin-Cameron Group, Inc. dated May 16, 2019 and revised through August 13, 2019. - "Lower Level Floor Plans Sutton Street Apartments", Sheets PA.00, PBC.00, PB.00 & PC.00 by R.A. Schaeffer & Q.M. White, Architects, Dated July 25, 2019 "Multi-family Residential Development at 505 Sutton Street, Notch Andover, Massachusetts" Swept Path Analysis dated August 13, 2019. We offer the following in response to the Engineering Corp (TEC) comments: 12. Engineering Comment. The size and scope of the project may result in a significant number of children needing access to buses during the school year. The Applicant should dedicate space along the site driveways to support sidewalks connections to Sutton Street to, at a minimum,provide access for school children to the potential bus stop location. In addition, the Town should consider a requirement that the Applicant provide, at a minimum, a standing pad along the roadway edge to serve as a safe location for children to gather while waiting for a school bus. MCG Response:The land at the roadway edge is owned and maintained by the town of North Andover.The Applicant is not proposing any work within the town right of way and wilt defer to the town on this matter. 13. Engineering Comment. There are currently no sidewalks provided along Sutton Street in the vicinity of the project. With a significant increase in potential pedestrian traffic to/from the site, the close proximity to the McEvoy Fields, a need for safe location for children to gather while waiting for a school bus, and available Town right-of-way- the Town should consider requesting the Applicant provide new sidewalk along the site frontage with connection to McEvoy Field to the east CIVIL ENGINEERS ® LAND SURVEYORS 0 ENVIRONMENTAL CONSULTANTS • LAND USE PLANNERS 66 Elm Street, Danvers, MA 01923 978.777.8586 FAX 978.774.3488 Providing Professional Services Since 1978 www.morincameron.com i i North Andover Planning Board 2 August 13, 2019 MCG Response: See response to comment 12, above. 14. Engineering Comment: The project proposes to provide 215 off-street parking spaces including ten (10)handicap spaces For the proposed 136 housing units, the Town of North Andover requires 224 off street parking spaces(§ 195-8.4). The TIA denotes that the site will provide sufficient parking for the site;however, the Applicant has not provided back-up data to support the statement(i.e. ITE Parking Generation or Urban Land Institute, etc.). The Applicant should provide back- up data to support the request for Special Permit. MCG Response: The current market parking demand for midrlse apartments is 1.5 spaces per unit. The provided ratio of 1.57 spaces per unit. This parking ratio exceeds the average statistical demand for parking in a mid-rise apartment of 1.35 spaces per unit (Reference.- Institute of Transportation Engineers.-Parking Generation Manual, 41h Edition). 15. Engineering Comment., The Site Plans do not provide the layout of garaged parking within each of the buildings on-site. The width of the buildings and the potential location of support columns may not provide sufficient maneuverability for vehicles within the building, The Applicant should provide a parking layout/traffic circulation plan for the proposed parking garages. A key aspect of the plan should note whether each garaged space is assigned by resident as the building width may not support a passenger vehicle or pick-up truck to turnaround should spaces not be available. MCG Response: The parking layouts for the building are attached hereto and are adequate for full size garage parking and aisle widths. The garage parking space assignment will be determined prior to occupancy. 16. Engineering Comment.Ensure the project will provide sufficient space along the private drive for a Town of North Andover fire apparatus to turn around. Upon application of a turning template, should a fire apparatus not be able to complete a full U-turn, the Applicant should consider modifications at these points to further enlarge the roadway hammerheads and/or provide for an engineered pervious area beyond the asphalt to allow for complete turns. MCG Response: A swept path analysis for the North Andover fire truck has been included hereto. 17. Engineering Comment: The Applicant should provide a vehicular circulation plan which shows that a garbage truck(front-loading) can adequately circulate the site and access the dumpster enclosures Note that the truck should maintain the same directional flow during pick-up as traditional vehicles. MCG Response:The dumpster enclosure was located to create one common space on the site for waste disposal.This will reduce the impact of garbage nuisance due to noise,odor or pests. The site provides sufficient maneuverability for a fire truck and will therefore also be able to. accommodate a garbage truck.The intent of the waste pickup design is for the garbage truck to pull into the waste pickup area and back out to the drive aisles where it can turn and follow the fire truck route in a clockwise direction back to the main egress. 18. Engineering Comment Several locations within the site are candidates for stop-signs and stop-bars to control perpendicular traffic at a main drive aisle; or at the major entranc%xit points. Where stop signs are shown on the plan, a stop-bar should be included to accompany i North Andover Planning Board 3 August 13, 2019 j the sign. Some key locations on the plans depict both bar and signage. The Applicant shall consider installation ofstop sign and stop-barat all those perpendicular locations where minor drive-aisles meet main drive aisles. For instance, the garage exit from Building #2 onto the garage exit from Building#1. i MCG Response: The anticipated peak trips from the underground parking garages do not necessitate a stop line and sign. The garages will be used solely by residents of the buildings who will be familiar with the access and circulation.There is excessive driver visibility between the garages. 19. Engineering Comment. There is currently no depiction of stop-sign at the site driveway at Sutton Street. MCG Response:A stop sign was added to sheet C3 at Sutton Street. 20. Engineering Comment.• Where additional sidewalk connectivity(from previous comments) is added to the plans, the Applicant shallprovide pedestrian crossing signage at the marked crosswalk/uncontrolled location within the site. This signage would be superseded should a stop-sign be warranted at this location. MCG Response: See responses to comments 12 & 13, above. The applicant will defer to the town on these matters. We trust this information adequately addresses your comments regarding the 505 Sutton Street Site Plan Review application plans. If you have any questions, please do not hesitate to contact our office at (978) 777-8586. Very Truly Y urs, T;MOI�f'-C AERON GROUP, IN—c—Seron, PE P SPC/abr Attachments cc: TEC Corporation Sutton Street Development, L.L.0 North Andover Planning Board X:\Minco\3454\Docs\Peer Review Comments13454 Engineering Response Letter Traffic Review 4 The M6rin Ca E f✓ )��'�; r}I�9J��/'������ l���N�I ��1 i' ��/+7�i.��n�e Jy y���)�,�✓ E I � August 13, 2019 North Andover Planning Board C/o Eitan Goldberg, Chair Town of North Andover 120 Main Street North Andover, MA 01845 RE; Response to Comments Application for Site Plan Approval 505 Sutton Street/Sutton Street Redevelopment, LLC Dear Members of the Board: On behalf of the owner, Sutton Street Redevelopment, LLC (Applicant), The Morin-Cameron Group, Inc. (MCG) has provided the following responses to the Town of North Andover Division of Public Works (DPW) comments issued on June 27, 2019. The Town comments are listed below in italics,with MCG's response following. Included with this submission are the following: - "Multifamily Site Development Plans in North Andover, Massachusetts, 505 Sutton Street" by The Morin-Cameron Group, Inc, dated May 16, 2019 and revised through August 13, 2019. We offer the following in response to the Public Works Division comments; 1. Engineering Comment:A triple water main connection is required in Sutton Street. Two 12- inch and one 8-inch valves shall be installed. The work will require the water main to be shut down and therefore will need to be closely coordinated with the Water Department and nearby water customers. MCG Response: The recommended gate valves and tees have been added to sheet C.6. The water- main shut down will be coordinated with the Water Department and water customers. A note has been added to sheet C.6 to this extent. 2. Engineering Comment. The existing domestic water service line shall be terminated at the main line in Sutton Street. MCG Response: The location of the existing domestic water service line is unknown, however, a note has been added to sheet C.3 to terminate at the main line in Sutton Street. 3. Engineering Comment.• The Water Department intends on replacing the nearby fire hydrant on Sutton Street and will eliminate the existing 4"fire line at the same time. We anticipate this work being done around the same time as the building demolition. MCG Response: Replacement of the hydrant with a new 6" service is supported by the Applicant as this will provide better flow for the public use and proposed senior center. CIVIL ENGINEERS ® LAND SURVEYORS ENVIRONMENTAL CONSULTANTS ® LAND USE PLANNERS 66 Elm Street, Danvers, MA 01923 978.777.8586 FAX 978.774.3488 Providing Professional Services Since 1978 www.morincameron.com i I North Andover Planning Board 2 August 13, 2019 4, Engineering Comment Based on the size of the buildings, a 3-inch compound meter shall be installed in each building. MCG Response: No response required. 5. Engineering Comment All proposed water mains shall be privately owned and maintained. MCG Response: No response required. 6. Engineering Comment,•All hydrants shall be Clow Eddy, open left. MCG Response: Water and Fire Note 3 has been added to sheet C.6 for all hydrants to be Clow Eddy, open left. 7. Engineering Comment: The existing sewer service line shall be terminated at the main line in Sutton Street. MCG Response: A note has been added to sheet C.3 to this extent. 8. Engineering Comment: Since the proposed grading along the shared access driveway extends onto the abutting Senior Center project area, site grading shall be coordinated with the Senior Center site construction. MCG Response:A leader was added to Sheet C.5 to coordinate grading with the senior center construction. We trust this information adequately addresses your comments regarding the 505 Sutton Street Site Plan Review application plans. If you have any questions, please do not hesitate to contact our office at (978) 777-8586. Very TrulyrY~o r , THE M{7R1 E ON GROUP, INC. Sc�q ameron, PE P c al SPC kmm Attachments cc. North Andover Department of Public Works Sutton Street Development, LLC X\Minco134541Docs\Peer Review Comments\3454 Response Letter Engineering The M66n-Cameron x August 13, 2019 North Andover Planning Board C/o Eitan Goldberg, Chair Town of North Andover 120 Main Street North Andover, MA 01845 RE: Response to Comments Application for Site Plan Approval 505 Sutton Street/Sutton Street Redevelopment, LLC Dear Members of the Board: On behalf of the owner, Sutton Street Redevelopment, LLC (Applicant), The Morin-Cameron Group, Inc. (MCG) has provided the following responses to the Department of Public Health comment issued on June 10, 2019, The Department of Public Health comment is listed below in italics, with MCG's response following. Included with this submission are the following: - "Multifamily Site Development Plans in North Andover, Massachusetts, 505 Sutton Street" by The Morin-Cameron Group, Inc. dated May 16, 2019 and revised through August 13, 2019. We offer the following in response to the Department of Public Health comment: 1. Department of Public Health Comment.• Site plans seem pretty straight forward and they have a dumpster enclosure between buildings 7 and Z. Would they consider putting in another dumpster adjacent to building 3?Not required since they do have one but it will have to be sized appropriately for the number of units proposed. Buildings will have to meet housing code requirements for multi-unit rental properties but this will be looked at when building permit applications are submitted. Let me know if you have any other questions. MCG Response: A dumpster location was not provided adjacent to building 3 to limit the impact on the abutting residential properties.The location at the underground garage exit was optimal as it is anticipated that the majority of residents will bring trash down via the garage and drive the waste to this location.This is the most convenient and efficient space on the property for refuse and a loading space was provided to allow cars to drop off with more ease after exiting the garage.The space provided is sufficient for the number of units with proper pickup oversight by the owner. We trust this information adequately addresses your comment regarding the 505 Sutton Street Site Plan Review application plans. CIVIL ENGINEERS a LAND SURVEYORS • ENVIRONMENTAL CONSULTANTS ® LAND USE PLANNERS 66 Elm Street, Danvers, MA 01923 978.777.8586 FAX 978,774.3488 Providing Professional Services Since 1978 www.morincameron.com North Andover Planning Board 2 August 13, 2019 If you have any questions, please do not hesitate to contact our office at (978) 777-8586, Very Truly You THE MORI MERON GROUP, S t me on, PE cipal. SOC/krnm Attachments cc: North Andover Department of Public Health Sutton Street Development, LLC X:1Minco13454\Docs\Peer ReView Comments\3454 Response Letter Public Health i 'I The M6rin-Cameron .......... August 13, 2019 North Andover Planning Board C/o Eitan Goldberg, Chair Town of North Andover 120 Main Street North Andover, MA 01845 RE: Response to Comments Application for Site plan Approval 505 Sutton Street/Sutton Street Redevelopment, LLC Dear Members of the Board: On behalf of the owner, Sutton Street Redevelopment, LLC (Applicant), The Morin-Cameron Group, Inc. (MCG) has provided the following responses to the Fire Department comments issued on June 11, 2019. The Fire Department comments are listed below in italics, with MCG's response following. Included with this submission are the following: "Multifamily Site Development Plans in North Andover, Massachusetts, 505 Sutton Street" by The Morin-Cameron Group, Inc, dated May 16, 2019 and revised through August 13, 2019. "Multi-family Residential Development at 505 Sutton Street, North Andover, Massachusetts" Swept Path Analysis dated August 13, 2019. Fire Department Comments 1-7 & 9 relate to the building construction and do not require an engineering response. We offer the following in response to Fire Department comment 8: 8. Fire Department Comment:A swept path analysis be performed of the site and parking areas to ensure FD apparatus has adequate access to the,buildings in accordance with 527 CMR Ch 18, MCG Response:A swept path analysis has been completed and a figure has been included herein to demonstrate fire department access to the building. We trust this information adequately addresses your comments regarding the 505 Sutton Street Site Plan Review application plans. CIVIL ENGINEERS • LAND SURVEYORS • ENVIRONMENTAL CONSULTANTS • LAND USE PLANNERS 66 Elm Street, Danvers, MA 01923 978.777.8586 FAX 978.774.3488 Providing Professional Services Since 1978 www.morincameron.com 1 North Andover Planning Board 2 August 13, 2019 If you have any questions, please do not hesitate to contact our office at (978) 777-8586. SMERON GROUP, INC. n, PE SPC/kmm Attachments cc: North Andover Fire Department Sutton Street Development, LLC X:\Minco134541Docs\Peer Review Comments13454 Response Letter Fire i The M6rin-Cameron ' ..... i August 13, 2019 North Andover Planning Board C/o Eitan Goldberg, Chair Town of North Andover 120 Main Street North Andover, MA 01845 RE; Response to Comments Application for Site Plan Approval 505 Sutton Street/Sutton Street Redevelopment, LLC On behalf of the owner, Sutton Street Redevelopment, LLC (Applicant), The Morin-Cameron Group, Inc. (MCG) has provided the following responses to the TEC Company peer review comments issued on June 27, 2019. The Peer Review comments are listed below in italics,with MCG's response following. Included with this submission are the following: - "Multifamily Site Development Plans in North Andover, Massachusetts, 505 Sutton Street" by The Morin-Cameron Group, Inc. dated May 16, 2019 and revised through August 13, 2019. - "Lower Level Floor Plans Sutton Street Apartments", Sheets PA.00, PBC.00, PB.00 & PC.00 by R.A. Schaeffer & D.M. White, Architects, Dated July 25, 2019 - "Hydrant Flow Test and Hydraulic Summary" by The Morin-Cameron Group, Inc. dated November 1, 2016 - "Proposed Gravity Sewer Pipe at 505 Sutton Street"Calculations by The Morin-Cameron Group, Inc. dated July 26, 2019. We offer the following in response to the Engineering Corp (TEC) comments; 1. Engineering Comment.- It should be noted that the Applicant is requesting the following Special Permits as noted in their application narrative,- a, Section 195-4.8,0- to allow multifamily housing in Business 2 district; b. Section 195-2.2(21)- to allow a shared common driveway c. Section 195-8.8- to allow up to 14 park spaces facing each other between landscape islands where a maximum of 10 is allowed,' d Section 195-8.8 0 to reduce the total number of parking spaces required to 215 from 224 which provides a ratio of 1.56 spaces per dwelling unit; e. Section 195-8.10-special permit for construction of new buildings exceeding 2,000 square feet of gross floor area and the addition of more than five (5)parking spaces. he applicant should note that this project will be subject to an impact fee as stated in Section.3 of the Tbwn's Water Use Mitigation Plan, (WOMP) which states: MCG Response: No response required, CIVIL ENGINEERS ® LAND SURVEYORS ® ENVIRONMENTAL CONSULTANTS LAND USE PLANNERS 66 Elm Street, Danvers, MA 01923 978.777.8686 FAX 978.774.3488 Providing Professional Services Since 1978 www.morincameron.com i North Andover Planning Board 2 August 13, 2019 2. Engineering Comment; The applicant will also be requesting waivers from the following sections of the Town of North Andover Zoning Bylaws; a. Section 195-8.14,E - several sections within the site plan review submission requirements. For full detail, refer to the special permit package; b. Section 195--7.4F -- to allow height increase in the B-2 district to 55' from 35' to accommodate a housing density of 136 rental units, c. Section 19508.5A & 8.5C(3) - allow a 36' wide curb cut where 25' is the maximum allowed. MCG Response:The applicant is withdrawing the waiver request for the 36'wide curb cut.This curb cut is located on the senior center property and, therefore, the waiver will be requested by the senior center development. 3. Engineering Comment. The Applicant should include a consistent limit of work across all of the site plan sheets. The limit of work should include all proposed grading work on the western side of the property. MCG Response: The limit of work tine has been adjusted to include proposed grading along the western edge of the property. A note has been added to sheet C5 to coordinate site grading with the senior center construction. 4. Engineering Comment. The Applicant should label the approximate Watershed Protection District on site plans and should determine if a permit is required for the proposed work within this district, MCG Response: The Watershed Protection District is [abetted on the site plans.The Applicant has reviewed the requirements of the District with North Andover Planning staff and determined that a Watershed Protection Special Permit is not needed. 5. Engineering Comment: The project is proposing garage parking totaling 120 spaces. It appears that the site layout provides garage access to Buildings I and 2, however Building 3 is labeled for garage spaces on sheet C.4. The applicant should provide parking layouts within the proposed buildings with dimensions for parking spaces and drive aisles. MCG Response: Access to Building 3 parking is through the entrance at Building 2. The buildings are proposed to have a single connected garage. The proposed first floor patio is above this proposed garage. The layout provides for 119 underground spaces. The waiver request for parking reduction to 215 spaces has been updated to 214 spaces to account for this change, Parking layout sheets for all buildings have been included with this submission, 6. Engineering Comment: The Applicant should provide the required handicapped parking calculations based on Chapter 180-2 of the Town of North Andover Bylaws and the Architectural Access Board regulations, as well as the provided spaces within the parking schedule or a parking table, MCG Response: The handicap parking calculations from the North Andover Bylaws and Architectural Access Board regulations have been added to the parking table on sheet CA. 7. Engineering Comment: The Applicant should show the resource area delineation flags that have been previously approximated upon an approved order of resource area determination issued by the Town of North Andover on Oct 27,, 2016 i North Andover Planning Board 3 August 13, 2019 MCG Response: These flags cannot be shown as they fall on private property. The Conservation Commission previously reviewed the wetland and issued a negative determination on October 27, 2016, 8. Engineering Comment. The project will likely require a Notice of Intent filing with the Conservation Commission for the proposed work located within the 100-foot buffer zone to a resource area. MCG Response:A Notice of Intent will be filed with the Conservation Commission. 9. Engineering Comment, TEC recommends that the Board require a traffic study be prepared to review access/egress operations and safety for the proposed shared driveway connection to Sutton Street. MCG Response.A traffic study was conducted and the report has been submitted to the Town under separate cover. 10. Engineering Comment.- The Applicant should provide a snow storage area on site that limits draining and runoff to abutting properties and direct melting snow into the proposed storm water system for treatment MCG Response: Snow storage has been shown only in areas where the grade wit,result in the majority of the snow draining towards the catch basins and the underground systems on site. 11. Engineering Comment., The Applicant should coordinate with the Town of North Andover Fire Department to confirm drive aisles, buildings, utilities and amenities are all fire accessible. MCG Response: The Fire Department has reviewed the project and provided comments. 12. Engineering Comment. TEC encourages the Applicant to coordinate directly with the abutting residential owners to design a "residential buffer zone" that is amendable to all parties. MCG Response:The Applicant is working with the North Andover Boards and abutters on this matter. The existing trees were surveyed and added to the plans in order to determine which trees can be preserved during construction. The rear of the property was regraded to pull the limit of work closer to the building to save more trees along the back property line.A note was added to sheet C3 to preserve trees along the rear property line where possible. A note was added to the cover sheet C1 to coordinate a preconstruction site walk with the Town of North Andover staff to assess the trees that will remain. A Tree Elevations sheet by Radner Design Associates was added to the landscape plans to illustrate the proposed tree buffer along the residential property line. 13. Engineering Comment:, The Applicant should review the proposed recycling and trash to evaluate if a larger container is needed for the number of proposed dwellings. Will this be enough waste storage?Can another enclosure be added around Building 3 to alleviate over packing of the current enclosure?Additionally is there enough space fora waste truck to enter without blocking the proposed garage drive aisles between Buildings 1 and 2? MCG Response: The Applicant has evaluated the size of the proposed waste enclosure to ensure it will be sufficient for the size of the project. The location for the solid waste disposal North Andover Planning Board 4 August 13, 2019 MCG Response: The Applicant has evaluated the size of the proposed waste enclosure to ensure it will be sufficient for the size of the project. The location for the solid waste disposal was placed at the exits of the driveways to allow residents to drive and drop off waste when exiting the garage. Pickup times will be during off peak hours and will take only a few minutes so this is not anticipated to be an issue. 14. Engineering Comment. The Applicant should show trees/shrubs to be removed within L 1.1 Planting Plan and the legend if applicable. MCG Response: A note has been added to the cover sheet to provide a preconstruction site walk with North Andover town staff to evaluate the trees on site, is. Engineering Comment, The Applicant should provide additional detail on the proposed wall on the eastern property line (top of wall, bottom of wall spot grades), It is unclear if the Applicant is proposing work on the adjacent property to construct this wall. MCG Response: Spot grades have been added to the plan. The existing retaining wall for the abutting property is encroaching into the subject property,The proposed wall will reconstruct this wall along the property line to remove the encroachment. No work is proposed on the abutting property. 16. Engineering Comment. The Applicant should call out the existing wooded areas to remain surrounding the property either be leader or within the legend on plan set L 1.1 Planting Plan. MCG Response:The wooded area is illustrated visually on the planting plan.A preconstruction meeting with town staff will take place to determine the condition of the trees and which trees can remain. 17. Engineering Comment. The Applicant should coordinate with the Town of North Andover Department of Public Works to determine if adequate water capacity exists for the domestic and fire prevention lines As currently drawn, the 4-inch domestic water service is tapped off of the 6-inch fire suppression services(building 2&3). MCG Response:A hydrant test was performed in 2016 to determine the capacity of the system In this location. The capacity is sufficient to support the project. A copy of the hydrant test results has been attached to this report. 18. Engineering Comment. TEC recommends that the Applicant install a sidewalk connection to Sutton Street on at least one side of the proposed shared driveway. MCG Response: A sidewalk connection to Sutton Street has been added to the plans. 19. Engineering Comment:Based on test pit information, it appears that the garage floors may be construction below the estimated seasonal high groundwater. The Applicant should clarify if a sump pump orpermanent dewatering system will be proposed, and where the effluent will be directed, MCG Response: A gravity foundation drain will be installed around the perimeter of the building and will be piped into the closed drainage system. These pipes have been added to the plans, i North Andover Planning Board 5 August 13, 2019 20. Engineering Comment: TEC recommends a minimum horizontal separation of 10-feet between the proposed sewer infrastructure and the stormwater infiltration systems (front of building 1), MCG Response: Due to the limited space in front of the building, 10 feet of separation is not possible between the drainage and sewer lines. The sewer in this area will be sleeved and a note has been as Sewer Note 5 on the cover sheet C-1 to indicate this, 21. Engineering Comment. TEC recommends that the Applicant provide a sewer pipe sizing calculation to confirm adequate capacity exists for all three buildings, MCG Response: The sewer pipe sizing is more than adequate to for the expected flow from a project of this sue. Please see attached sizing calculations herein. We trust this information adequately addresses your comments regarding the 505 Sutton Street Site Plan Review application plans. If you have any questions, please do not hesitate to contact our office at (978) 777-8586. Vk—A TON GROUP, INC. cPrS Attachments cc; TEC Corporation Sutton Street Development, LLC XAMinco\3454\Docslpeer Review Comments13454 Engineering Response Letter I The M6rin-Cameron I August 13, 2019 i i North Andover Planning Board C/o Eitan Goldberg, Chair Town of North Andover 120 Main Street North Andover, MA 01845 RE: Response to Comments Application for Site Plan Approval 505 Sutton Street/Sutton Street Redevelopment, LLC i Dear Members of the Board: On behalf of the owner, Sutton Street Redevelopment, LLC (Applicant), The Morin-Cameron Group, Inc. (MCG) has provided the following responses to the Town of North Andover Stormwater Peer Review report dated July 1, 2019. The Peer Review comments are listed below in italics, with MCG's response following. Included with this submission are the following: - "Multifamily Site Development Plans in North Andover, Massachusetts, 505 Sutton Street" by The Morin-Cameron Group, Inc. dated May 16, 2019 and revised through August 13, 2019. - Revised Proposed Conditions Hydrologic Analysis HydroCAD. - Stormwater Management Key Plan dated August 13, 2019. - Revised Stormwater Management Calculations dated August 13, 2019. - Block Diagram prepared by The Morin-Cameron Group, Inc. dated August 13, 2019. We offer the following in response to the Horsley Witten Group Stormwater Review comments: 1.a Engineering Comment, The Applicant has analyzed the existing and proposed storm water discharge rates from the project site at the property boundaries, At the south property boundary, the development discharges Stormwater overland towards an isolated vegetated wetland. The flow is not significant towards this resource area and erosion is not anticipated. MCG Response: The site does not drain towards the offsite wetland in either the existing or proposed condition. There is an existing berm along the edge of the property that directs the water towards the east property line, away from the edge of the isolated vegetated wetland. 1.a Engineering Comment: The Applicant will also be discharging a majority of the proposed flow towards the municipal drainage system in Sutton Street To verify that the outlet of the municipal system will not cause erosion in waters of the Commonwealth HW recommends that the Applicant provide a narrative describing where the municipal system currently outlets and document that no erosion is currently occurring. CIVIL ENGINEERS ® LAND SURVEYORS ® ENVIRONMENTAL CONSULTANTS ® LAND USE PLANNERS 66 Elm Street, Danvers, MA 01923 978.777.8586 FAX 978.774.3488 Providing Professional Services Since 1978 www.morincameron.com North Andover Planning Board 2 August 13, 2019 MCG Response:The municipal system outlets off the south side of Osgood Street.A field visit conducted by The Morin-Cameron Group, Inc, identified this are as densely vegetated. No outlet structure was identified and there was no sign of erosion or scour at the record outlet locations. The field crew followed the topography to the nearest wetland and did not observe any erosion in or upstream of the wetlands, 2.a Engineering Comment, The Applicant has provided clear documentation to illustrate that the post- development peak discharge rates do not exceed pre-development rates, However, the bottom of the stone for each subsurface system listed on Sheet C. 12 does not all correlate with the bottom of the stone elevations provided in the HydroCAD modeling calculations. HW recommends that the Applicant revisit the plan and calculations for Infiltration Systems#2, #3, and#4, as well as Detention System #1, MCG Response:The system locations and elevations were revised to demonstrate compliance with the 2 feet of separation to groundwater. 2.b Engineering Comment For clarity HW recommends that the Applicant list the Retain-It chamber size on Sheet C 12 for each of the individual systems and verify that the correlating details are provided on Sheet C,13, MCG Response:The Retain-it chamber sizes are listed in the leader detailing the total number of units. These sizes have been verified with the correlating detail on sheet C.13. 2.c Engineering Comment: The Applicant has conducted soil evaluations within each of the subsurface systems and has provided the soil logs on Sheet C.7. HW requests that the surface elevations of the test pits within the infiltration systems be added to the test logs. When responding to comment 2a. above HW recommends that the Applicant verify that it is providing adequate separation to groundwater from the bottom of the stone, specifically for Infiltration Systems#3 and#4. MCG Response: The existing surface elevations of the test pits have been added to the test logs for all test pits. 2.d Engineering Comment. The Applicant has regraded the entire site including along the western,southern,and eastern property boundaries, Under existing conditions, the stormwater flows within the site boundaries towards #19 Surry Drive (west boundary)and#946 Osgood Street (east boundary), Under proposed conditions the site sheet flows towards additional abutting properties, including#25, #35, #43, #51, and#59 Surrey Drive, HW recommends that the Applicant clarify whether the abutting property owners will receive more stormwater under proposed conditions than they do under existing conditions, MCG Response:The intent of the grading along the property boundaries is to direct all water back towards design point 3 or the catch basins in the parking area. Sheet CA has been revised to add flow arrows. #51 and #S9 Surrey Drive receive no stormwater during existing or proposed conditions due to the existing berm described in response 1.a. Due to the reduced tributary area, #25, #35, &#43 Surrey Drive will receive less runoff, The grades along this area of the site promote sheet flow from vegetated areas only. i i 1 North Andover Planning Board 3 August 13, 2019 3.a Engineering Comment; In Appendix D of the Drainage Report, the Applicant has provided calculations to demonstrate that the infiltration systems are sized to capture and recharge the groundwater recharge volume for HSG C generated from the new impervious area. HW recommends that the Applicant revise the calculations for the provided recharge volume as needed in response to comment 9.a, above i MCG Response: The groundwater recharge calculations were revised and are attached hereto. 4.a Engineering Comment., TSS removal calculations are provided in Appendix 1 of the Drainage Report including the TSS removal provided by the pretreatment practices prior to the infiltration systems. HW recommends that the Applicant verify that the pretreatment provides the 44% TSS removal in accordance with Standard 6 and adjust the design as applicable. MCG Response: The pretreatment for all infiltration systems provides at least 44% TSS removal. The included TSS removal calculations that show less than 44% TSS removal are calculations for the catch basins to provide 25% pretreatment associated with the overall 80% TSS credit for infiltration basins, per the Massachusetts Stormwater Handbook. 5.a Engineering Comment., The proposed development of 136 residential units is not considered a L UHPPL therefore, Standard 5 is not applicable to this project, MCG Response: No response necessary. 5.a Engineering Comment.A portion of the project site lies within the North Andover Watershed Protection District, therefore Standard 6 is applicable. HW recommends that the Applicant verify that the design complies with the requirements of Standard 6 as described in the Massachusetts Stormwater Handbook, Chapter 9, Volume 1, page 15. MCG Response: The Applicant has reviewed the requirements of the District with North Andover Planning staff and determined that a Watershed Protection Special Permit is not needed. The design complies with the requirements of Standard 6. 7.a Engineering Comment; The proposed development is considered a new development with an increase of impervious area, therefore Standard 7is not applicable. MCG Response: No response necessary. 8.a Engineering Comment. The Applicant has provided erosion control notes on Sheet C 1, erosion control locations on Sheet C.3, and details on Sheet C.8, HW recommends that the Applicant verify that the contractor will use straw bales and not hay bales. MCG Response: The plans have been revised to specify 12" mulch sock, i 1 North Andover Planning Board 4 August 13, 2019 8.b Engineering Comment, HW recommends that the Applicant include a note on the plans stating that soil stockpiles must be kept outside of the 100-foot buffer zone. MCG Response: Erosion and Sedimentation Control note 6 on sheet CA has been updated to state that soil stockpiles must be kept outside of the 100-foot buffer zone, 9.a Engineering Comment: The Applicant has provided a long-term O&M Plan in the Drainage Report The O&M Plan should be a standalone document and include a simple sketch to clearly indicate the location of all stormwater practices to be inspected as well as locations for snow storage. HW recommends that the Applicant include a simple sketch that will be provided to the property owner. MCG Response: A stormwater management key plan has been added to the long-term O&M Plan and is submitted with this response letter. 9.b Engineering Comment- HW recommends that the property owner sign the O&M Plan in accordance with the North Andover Storm water Regulations MCG Response: The operation and maintenance plan will be signed prior to construction, 10,a Engineering Comment, The Applicant provided an Illicit Discharge Compliance Statement to be signed by the engineer in Appendix H of the Drainage Report. HW recommends that the illicit discharge statement be signed by the property owner prior to land disturbance. MCG Response:The applicant will sign the illicit discharge statement prior to land disturbance, 11.a Engineering Comment. HW recommends that the Applicant evaluate the volume of stormwater runoff in accordance with Section 7.2.8,E of the North Andover Stormwater Regulations It appears that the volume of stormwater discharging from the site at Design Point 1 in Sutton Street increases over existing conditions HWrecommends that the Applicant confirm that the municipal system has the capacity for the additional volume. MCG Response: The stormwater volume will result in an increase in volume only at design point 1. All other design points have reduced volumes, The table below summarizes the increase in volume for this design point, Design Point 1 Storm Event Existing Volume Proposed Volume (cf) Change in Volume (cf) (Acre-Ft) 1" storm 1,299 1,809 0.012 2-yr 10,254 16,876 0,197 10-yr 17,864 31,196 0.306 25-yr 23,752 42,803 0.437 100-yr 36,740 68,729 0.734 i North Andover Planning Board 5 August 13, 2019 In the existing conditions, during the 100 year storm, the runoff from the site to design point 1 bypasses the existing, undersized stormwater structures and flows overland through the abutting property towards Osgood Street, and the wetland surrounding Lake Cochituate. The proposed design includes more robust stormwater controls that will capture, detain and discharge water to the closed drainage system, thereby eliminating a significant source of runoff across a large commercial parking lot. The proposed site grading creates low points within the site that impound water within the property further decreasing the overland flow from the existing conditions. Although the benefits of these design considerations are not quantitatively measurable, the reduction in overland flow carrying sediment and pollutants across the abutting commercial lot will be a significant improvement to the Osgood Street layout and drainage system. A simple exhibit was prepared to illustrate this pre vs post condition and is attached hereto. We trust this information adequately addresses your comments regarding the 505 Sutton Street Site Plan Review application plans. If you have any questions, please do not hesitate to contact our office at (978) 777-8586, i Very Truly Y s, THE MO I ERON GROUPS l,N . Cott meron, PE Pri t SPC kmm Attachments cc: Horsley Witten Group, LLC Sutton Street Development, LLC X:1Minco134541Docs\Peer Review Comments13454 Engineering Response letter Stormwater f k The M6rin-Cameron 11.21 August 29, 2019 North Andover Planning Board C/o Eitan Goldberg, Chair Town of North Andover 120 Main Street North Andover, MA 01845 RE: Response to Comments Application for Site Plan Approval 505 Sutton Street/Sutton Street Redevelopment, LLC Dear Members of the Board; On behalf of the owner, Sutton Street Redevelopment, LLC (Applicant), The Morin-Cameron Group, Inc. (MCG) has provided the following responses to the Town of North Andover 211d Stormwater Peer Review report dated August 19,2019.The Peer Review comments are listed below in italics,with MCG's response following. Comments that require no further response from MCG have been omitted for clarity. Included with this submission are the following: - Sheet C.5 from "Multifamily Site Development Plans in North Andover, Massachusetts, 505 Sutton Street" by The Morin-Cameron Group, Inc, dated May 16, 2019 and revised through August 29, 2019. - Revised Proposed Conditions Hydrologic Analysis HydroCAD. - Retain-it Module Storage Volumes &Weight by Height We offer the following in response to the Horsley Witten Group Stormwater Review comments: 1.a Engineering Comment. The Applicant has analyzed the existing and proposed stormwater discharge rates from the project site at the property boundaries At the south property boundary, the development discharges stormwater overland towards an isolated vegetated wetland. The flow is not significant towards this resource area and erosion is not anticipated. MCG Response: The site does not drain towards the offsite wetland in either the existing or proposed condition. There is an existing berm along the edge of the property that directs the water towards the east property line, away from the edge of the isolated vegetated wetland. Engineering Comment 2.• The Applicant has responded that the Site does not drain towards the offsite wetland in either the existing orproposed condition. There is an existing berm along the edge of the property that directs the water towards the east property line, away from the edge of the isolated vegetated wetland. HW recommends that the Applicant note the berm on the site plans with a statement that the berm will remain as existing. MCG Response 2: A note has been added to sheet C.5 for the berm to remain. CIVIL ENGINEERS ® LAND SURVEYORS ® ENVIRONMENTAL CONSULTANTS ® LAND USE PLANNERS 66 Elm Street, Danvers, MA 01923 978,777.8586 FAX 978.774.3488 Providing Professional Services Since 1978 www.morincameron.com North Andover Planning Board 2 August 29, 2019 I 2.a Engineering Comment: The Applicant has provided clear documentation to illustrate that the post- development peak discharge rates do not exceed pre-development rates. However, the bottom of the stone far each subsurface system listed on Sheet C. 12 does not all correlate with the bottom of the stone elevations provided in the HydroCAD modeling calculations. HW recommends that the Applicant revisit the plan and calculations for Infiltration Systems 112, 113, and#4, as well as Detention System#1. MCG Response:The system locations and elevations were revised to demonstrate compliance with the 2 feet of separation to groundwater. Engineering Comment 2. The Applicant has revised the locations and elevations of the subsurface stormwater practices to demonstrate compliance with the 2 feet separation to groundwater, For clarity HW recommends that the Applicant property label 4P in the HydroCAD model as Detention System #1 and 5P as Infiltration System #4, MCG Response 2: The HydroCAD model has been revised to show 4P as Detention System#1 and 5P as Infiltration System #4. 2,b Engineering Comment: For clarity HW recommends that the Applicant list the Retain-It chamber size on Sheet C.12 for each of the individual systems and verify that the correlating details are provided on Sheet C.13. MCG Response:The Retain-it chamber sizes are listed in the leader detailing the total number of units. These sizes have been verified with the correlating detail on sheet C.13. Engineering Comment 2. The Applicant has listed the Retain It dimensions and total number of units for the five subsurface systems on Sheet C.12. The heights listed include 2.67'. 3.17; 4.17'. and 4.67'. The Details provided on Sheet C.13 indicate the heights to be 3'8"and 48' It appears that the Retain It Chambers comes in variable heights, HW recommends that the Applicant confirm that the heights proposed for the various systems are available as noted. MCG Response 2: The sizes for the systems are available as noted. The module height sheet from the manufacturer is included herein. 2.d Engineering Comment: The Applicant has regraded the entire site including along the western,southern,and eastern property boundaries Under existing conditions, the stormwater flows within the site boundaries towards #19 Surry Drive (west boundary)and#946 Osgood Street (east boundary). Under proposed conditions the site sheet flows towards additional abutting properties, including#25, #35, #43, #51, and#59 Surrey Drive. HW recommends that the Applicant clarify whether the abutting property owners will receive more stormwater under proposed conditions than they do under existing conditions. MCG Response: The intent of the grading along the property boundaries is to direct all water back towards design point 3 or the catch basins in the parking area. Sheet CA has been revised to add flow arrows, #51 and #59 Surrey Drive receive no stormwater during existing or proposed conditions due to the existing berm described in response 1.a, Due to the reduced tributary area, #25, #35, & #43 Surrey Drive will receive less runoff. The grades along this area of the site promote sheet flow from vegetated areas only. Engineering Comment 2: The Applicant has stated that the Intent of the grading along the property boundaries is to direct all water back towards design point 3 or the catch basins in the parking area. The Applicant stated further, that Sheet C.4 has been revised to add flow arrows. However, HW was not able to locate the flow arrows. HW recommends that the North Andover Planning Board 3 August 29, 2019 Applicant add a note for the contractor to grade the areas adjacent to the property boundaries to direct runoff into the parking lot. The Applicant also notes, that 1151 and#59 Surrey Drive receive no stormwater during existing or proposed conditions due to the existing berm described in response l.a. Due to the reduced tributary area, #25, 1135, &#43 Surrey Drive will receive less runoff. The grades along this area of the site promote sheet flow from vegetated areas only. HW is satisfied that the Applicant will not be directing more stormwater onto the adjacent properties than under existing conditions. MCG Response 2: A note was added to C,5 to grade areas adjacent to property boundaries to direct runoff into the parking lot. We trust this information adequately addresses your comments regarding the 505 Sutton Street Site Plan Review application pians. If you have any questions, please do not hesitate to contact our office at (978) 777-8586. Very Truly ours, THEM N-CAMERON GRP-UP-, -INC:-" Cott , Ca ron, PE Prin pal SPC/kmm Attachments cc: Horsley Witten Group, LLC Sutton Street Development, LLC i X:1Minco134541Docs\Peer Review Comments13454 Engineering Response Letter stormwater 2 i retain-it ° Module Storage Volumes & Weight by Height 5' tall (ID) Storage(tuft,) Weight(lbs,) 4.5' tall (ID) Storage(tuft,) Weight(lbs.) Corner(Multi Row) 270.50 13,857 Corner(Multi Row) 243.17 13,156.5 Perimeter(Multi Row) 280.89 12,298.5 Perimeter(Multi Row) 252.14 11,811 Center(Multi Row) 291.28 10,740 Center(Multi Row) 261.11 10,465.5 End(Single Row) 257.75 15,769.5 End(Single Row) 231.83 14,857.5 Center(Single Row) 270.50 13,857 Center(Single Row) 243.17 13,156.5 4' tall (ID) storage(tuft.) Weight(lbs.) 3.5' tall ON Storage(tuft.) Weight(lbs.) Corner(Multi Row) 215.83 12,457.5 Corner(Multi Row) 188.50 11,7S7 Perimeter(Multi Row) 223.39 11,323.5 Perimeter(Multi Row) 194.64 10,836 Center(Multi Row) 230.94 10,191 Center(Multi Row) 200.78 9915 End(Single Row) 205.92 13,944 End(Single Row) 180.00 13,032 Center(Single Row) 215.83 12,457.5 Center(Single Row) 188.50 11,757 j 3' tall (ID) Storage(tuft.) Weight(lbs.) 2.5' tall (ID) Storage(tuft.) Weight(lbs.) Corner(Multi Row) 161.17 11,056.5 Corner(Multi Row) 133.83 10,357.5 Perimeter(Multi Row) 165.89 10,348.5 Perimeter(Multi Row) 137.14 9861 Center(Multi Row) 170.61 9640.5 Center(Multi Row) 140.44 9366 End(Single Row) 154.08 12,120 End(Single Row) 128.17 11,206.5 Center(Single Row) 161,17 11,056.5 Center(Single Row) 133.83 10,357.5 2' tall (ID) Storage(tuft.) Weight(lbs.) IN tall (ID) Storage(tuft.) Weight(lbs.) Corner(Multi Raw) 105.50 9657 Corner(Multi Row) 79.17 8956.5 Perimeter(Multi Row) 108.39 9373.5 Perimeter(Multi Row) 79.17 8956.5 Center(Multi Row) 110.28 9090 Center(Multi Row) 79.17 8956,5 End(Single Row) 102.25 10,294.5 End(Single Row) 76,33 9382.5 Center(Single Row) 106.50 9657 Center(Single Row) 79,17 8956.5 I' tall (ID) Storage(tuft.) Weight(Ibs.) Corner(Multi Row) 51.83 8257.5 Perimeter(Multi Row) 51.83 8257,5 Center(Multi Row) 51.83 8257.5 End(Single Row) 50.42 8469 Center(Single Row) 51.83 8257.5 • For Multi-level systems with an open top lower level,add 21.50 tuft of storage to each lower level module 1 i PS9 PS3 PS4 P55 5P ¢— PS11 PS8 \ � Infiltration System 1P 4P 4— P51 PS8 6P PS1 PS7 Retain It Y ©P1 Detention System 1 ` Infi! lion Trench PS1a —D sP � � 2P �- PS2 \xJ©P2 DP3 �P4 €?bp5 Retain it Retain It Subcat Reach pn III lit Routing Diagram for 505 Sutton Proposed Conditions Hydrologic Analysis Prepared by Microsoft, Printed 8/29/2019 HydroCAi]®10.00-13 s/n 00401 ©2014 HydroCAD Software Sol ulions LLC 505 Sutton Proposed Conditions Hydrologic Analysis Type it/24-hr I"Storm Rainfall=1.00" Prepared by Microsoft Printed 8/29/2019 HydroCAD810.00-13 s/n 00401 ©2014 HydroCAD Software Solutions LL.0 Page 2 Summary for Subcatchment PSI: Runoff - 0.43 cfs @ 12.09 hrs, Volume= 1,319 cf, Depth= 0.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1" Storm Rainfall=1.00" Area (so CN Description * 3,170 74 >75% Grass cover, Good, HSG C 23,273 98 Paved parking, HSG C 661 98 Roofs, HSG C 987 98 Unconnected pavement, HSG C 28,091 95 Weighted Average 3,170 11.28% Pervious Area 24,921 88.72% Impervious Area 987 3.96% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (fuft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PSI 0: Runoff - 0.28 cfs @ 12.08 hrs, Volume= 912 cf, Depth= 0.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1" Storm Rainfall=1.00" Areas CN Descri tion 13,844 98 Roofs, HSG C 13,844 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (fuft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PSI 1. Runoff - 0.31 cfs @ 12.08 hrs, Volume= 1,003 cf, Depth= 0.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1" Storm Rainfall=1.00" Area (so CN Description 15,214 98 Roofs HSG C 15,214 100,00% Impervious Area 505 Sutton Proposed Conditions Hydrologic Analysis Type I1124-hr I"Storm Rainfall=1.00" Prepared by Microsoft Printed 8/29/2019 H droCAD® 10.00-13 s1n 00401 ©2014 HydroCAD Software Solutions LLC Page 3 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, ................._.. Summary for Subcatchment PSI 2: Runoff - 0.00 cfs @ 14.78 hrs, Volume= 25 cf, Depth= 0.02" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1" Storm Rainfall=1.00" Area (sD CN Description 12,822 74 >75% Grass cover, Good, HSG C 12,822 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 6.0 Direct Entry, Summary for Subcatchment PS2: Runoff - 0,19 cfs @ 12.09 hrs, Volume= 578 cf, Depth= 0.50" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1" Storm Rainfall=1.00" Areas CN Descri tion 2,572 74 >75% Grass cover, Good, HSG C 6,226 98 Paved parking, HSG C 1,474 98 Roofs, HSG C 3,495 98 Unconnected pavement, HSG C 13,767 94 Weighted Average 2,572 18.68% Pervious Area 11,195 81.32% Impervious Area 3,495 31.22% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) &0 Direct Entry, Summary for Subcatchment PS3: Runoff = 0.08 cfs @ 12.09 hrs, Volume= 259 cf, Depth= 0.36" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1" Storm Rainfall=1.00" 505 Sutton Proposed Conditions Hydrologic Analysis Type III 24-hr I"Storm Rainfall=1.00" Prepared by Microsoft Printed 8/29/2019 H droCAD® 10.00-13 sln 00401 ©2014 H droCAD Software Solutions LLC Page 4 Area (so CN Description 2,355 74 >75% Grass cover, Good, HSG C 5,874 98 Paved parking, HSG C 34 98 Roofs, HSG C 378 98 Unconnected pavement, HSG C 8,641 91 Weighted Average 2,355 27.25% Pervious Area 6,286 72.75% Impervious Area 378 6.01% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ftlsec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS4: Runoff = 0.01 cfs @ 12.32 hrs, Volume= 83 cf, Depth= 0.08" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1" Storm Rainfall=1.00" Area (so CN Description 8,762 74 >75% Grass cover, Good, HSG C 3,160 98 Paved parking, HSG C 11,922 80 Weighted Average 8,762 73.49% Pervious Area 3,160 26.51% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS5: Runoff - 0.07 cfs @ 12.10 hrs, Volume= 243 cf, Depth= 0.25" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1" Storm Rainfall=1.00" Area (sf) CN Description 4,846 74 >75% Grass cover, Good, HSG C 5,452 98 Paved parking, HSG C 95 98 Roofs, HSG C _ 1,133 98 Unconnected pavement, HSG C 11,526 88 Weighted Average 4,846 42.04% Pervious Area 6,680 57.96% Impervious Area 1,133 16.96% Unconnected 506 Sutton Proposed Conditions Hydrologic Analysis Type I1124-hr I"Storm Rainfall=1.00" Prepared by Microsoft Printed 8/29/2019 H droCAD® 10.00-13 s/n 00401 ©2014 H droCAD Software Solutions LLC Page 5 Tc Length Slope Velocity Capacity Description min feet ft/ft (ft/sec) cfs 6.0 Direct Entry, Summary for Subcatchment PS6: Runoff - 0.00 cfs @ 14.78 hrs, Volume= 10 cf, Depth= 0.02" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1" Storm Rainfall=1.00" Area (sf) CN Description 5,343 74 >75% Grass cover, Good, HSG C 5,343 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (fUft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS7: Runoff - 0.00 cfs @ 14.78 hrs, Volume= 5 cf, Depth= 0.02" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1" Storm Rainfall=1.00" Area (so CN Description 206 74 >75% Grass cover, Good, HSG C 2,666 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS8: Runoff = 0.00 cfs @ 14.79 hrs, Volume= 40 cf, Depth 0.02" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1" Storm Rainfall=1.00" Area (sD CN Description 20,900 74 >75% Grass cover, Good, HSG C 20,900 100.00% Pervious Area 505 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr I"Storm Rainfall=1.00" Prepared by Microsoft Printed 8/29/2019 HydroCADO 10..00-13 sln 00401 0 2014 HydroCAD Software Solutions LLC Page 6 Tc Length Slope Velocity Capacity Description (miry) (feet) (ftlft) (ftlsec) (cfs) 4.9 50 0.0300 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 1.3 210 0.0290 2.74 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.0 20 0.3500 9.52 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 6.2 280 Total Summary for Subcatchment PS8A: Runoff 0.05 cfs @ 12.08 hrs, Volume= 168 cf, Depth= 0.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1" Storm Rainfall=1.00" Areas ON Description 587 98 Roofs, HSG C 1,965 98 Unconnected pavement, HSG C 2,552 98 Weighted Average 2,552 100.00% Impervious Area 1,965 77.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS9: Runoff = 0.37 cfs @ 12.08 hrs, Volume= 1,184 cf, Depth= 0.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1" Storm Rainfall=1.00" Area (so CN Description 17,961 98 Roofs, HSG C 17,961 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ftlsec) (cfs) 6.0 Direct Entry,.................................................................... Summary for Reach DPI: [40] Hint: Not Described (Outflow=I nf low) Inflow Area = 126,309 sf, 78.59% Impervious, Inflow Depth > 0.17" for 1" Storm event Inflow = 0.15 cfs @ 12.46 hrs, Volume= 1,809 of Outflow = 0.15 cfs @ 12.46 hrs, Volume= 1,809 cf, Atten= 0%, Lag= 0.0 min 3 1 505 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr I"Storm Rainfall=1.00" Prepared by Microsoft Printed 8/29/2019 HydroCAD010.00-13 s/n 00401 02014 HydroCAD Software Solutions LLC Page 7 Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs! 3 Summary for Reach DP2: [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 23,452 sf, 10.88% Impervious, Inflow Depth = 0.02" for 1" Storm event Inflow = 0.00 cfs @ 12.55 hrs, Volume= 42 cf Outflow = 0,00 cfs @ 12.55 hrs, Volume= 42 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 1 3 Summary for Reach DP3: [40] Hint: Not Described (Outflow=I nf low) Summary for Reach DP4: [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 12,822 sf, 0,00% Impervious, Inflow Depth = 0.02" for 1" Storm event Inflow = 0.00 cfs @ 14.78 hrs, Volume= 25 cf Outflow - 0.00 cfs @ 14.78 hrs, Volume= 25 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Summary for Reach DPS: [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 2,666 sf, 0.00% Impervious, Inflow Depth = 0.02" for 1" Storm event Inflow = 0.00 cfs @ 14.78 hrs, Volume= 5 cf Outflow - 0.00 cfs @ 14.78 hrs, Volume= 5 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Star-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Summary for Pond 1 P: Retain It Inflow Area = 31,945 sf, 75.90% Impervious, Inflow Depth = 0.55" for 1" Storm event Inflow = 0.45 cfs @ 12.09 hrs, Volume= 1,453 of Outflow - 0.11 cfs @ 12.49 hrs, Volume= 1,453 cf, Atten= 76%, Lag= 24.0 min Discarded = 0.03 efs @ 11.75 hrs, Volume= 1,225 cf Primary - 0.07 cfs @ 12.49 hrs, Volume= 228 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 505 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr I"Storm Rainfall=1.00" Prepared by Microsoft Printed 8/29/2019 HydroCAD®_10._00-13 s/n 00401 OO 2014 HydroCAD Software Solutions LLC Page 8 Peak Elev= 162.66' @ 12.49 hrs Surf.Area= 1,460 sf Storage= 464 of Plug-Flow detention time= 71.8 min calculated for 1,452 cf(100% of inflow) Center-of-Mass det. time= 71.8 min ( 873.7- 801.9 ) Volume Invert Avall.Storage Storage Description #1A 162.00' 867 cf 146.00'W x 10.001 x 5.17'H Field A 7,543 cf Overall - 5,376 cf Embedded = 2,167 cf x 40.0% Voids #2A 162.50' 3,870 cf retain_it 4.0' x 18 Inside#1 Inside= 84.0"W x 48.0"H => 28.87 sf x 8.001 = 230.9 cf Outside 96.0"W x 56.0"H => 37.33 sf x 8.001 = 298.7 cf 18 Rows adjusted for 286.9 cf perimeter wall 4,737 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 162.50' 12.0" Round Culvert L= 112.0' Ke= 0.500 Inlet/ Outlet Invert= 162.50'/ 153.84' S= 0.0773 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 162.50' 6.0"Vert. Orifice/Grate C= 0.600 #3 Device 1 164.50' 3.0"Vert. Orifice/Grate C= 0.600 #4 Device 1 166,40' 12.0" Horiz. OrificelGrate C= 0.600 Limited to weir flow at low heads #5 Discarded 162.00' 1.020 inlhr Exfiltration over Surface area Phase-In= 0.01' J)iscarded OutFlow Max=0.03 cfs @ 11.75 hrs HW=162.05' (Free Discharge) S=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.07 cfs @ 12.49 hrs HW=162.66' TW=0.00' (Dynamic Tailwater) L1=Culvert (Passes 0.07 cfs of 0.11 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.07 cfs @ 1.35 fps) 3=Orifice/Grate ( Controls 0.00 cfs) =OrificelGrate ( Controls 0.00 cfs) Summary for Pond 2P: Retain It Inflow Area = 13,767 sf, 81.32% Impervious, Inflow Depth = 0.50" for 1" Storm event inflow - 0.19 cfs @ 12.09 hrs, Volume= 578 cf Outflow - 0.02 cfs @ 11.88 hrs, Volume= 578 cf, Atten= 89%, Lag= 0.0 min Discarded = 0.02 cfs @ 11.88 hrs, Volume= 578 of Primary - 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs/3 Peale Elev= 162.53' @ 12.90 hrs Surf.Area= 900 sf Storage= 201 cf Plug-Flow detention time= 76.3 min calculated for 578 cf(100% of inflow) Center-of-Mass det. time= 76.3 min ( 909.1 - 832.8 ) I 505 Sutton Proposed Conditions Hydrologic Analysis Type Ill 24-hr I"Storm Rainfall=1.00" Prepared by Microsoft Printed 8/29/2019 HyroCAD® 10.00-13_s/n 00401 0 2014 HydroCAD Software Solutions LLC_ Page 9 j Volume Invert Avail.Stora e Storage Description #1A 162.00' 400 cf 50.00'W x 18.001 x 4.67'H Field A 4,200 cf Overall - 3,200 cf Embedded = 1,000 cf x 40.0% Voids #2A 162.50' 2,311 cf retain it 3.5' x 12 Inside #1 Inside= 84.0"W x 42.0"H => 25.10 sf x 8.001 = 200.8 cf Outside= 96.0"W x 50.0"H => 33.33 sf x 8.001 = 266.7 cf _ 6 Rows adjusted for 98.2 cf perimeter wall 2,711 cf Total Available Storage Storage Group A created with Chamber Wizard 1 Device Routing Invert Outlet Devices #1 Primary 162.50' 12.0" Round Culvert L= 23.0' Ke= 0.500 Inlet/Outlet Invert= 162.50' / 158.32' S= 0.1817 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 162.90' 4.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 163,80' 3.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 164.80' 4.0"Vert. Orifice/Grate C= 0.600 #5 Device 1 165,40' 12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #6 Discarded 162.00' 1.020 in/hr Exfiltration over Surface area Phase-In= 0.01' Discarded OutFlow Max=0.02 cfs @ 11.88 hrs HW=162.05' (Free Discharge) t-6=Exflltration (Exfiltration Controls 0.02 cfs) Primary OutFlow, Max=0.00 cfs @ 0.00 hrs HW=162.00' TW=0.00' (Dynamic Tailwater) t_1=Culvert ( Controls 0.00 cfs) 2=Orifice/Grate ( Controls 0.00 cfs) 3=Orlfice/Grate ( Controls 0.00 cfs) =Orifice/Grate ( Controls 0.00 cfs) 5=Orifice/Grate ( Controls 0.00 cfs) Summary for Pond 3P: Retain It Inflow Area = 13,844 sf,100.00% Impervious, Inflow Depth = 0.79" for 1" Storm event Inflow 0.28 cfs @ 12.08 hrs, Volume= 912 cf Outflow - 0.03 cfs @ 12.93 hrs, Volume= 912 cf, Atten= 91%, Lag= 50.6 min Discarded = 0.01 cfs @ 11.30 hrs, Volume= 854 cf Primary = 0.01 cfs @ 12.93 hrs, Volume= 59 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 163.57' @ 12.93 hrs Surf.Area= 612 sf Storage= 393 cf Plug-Flow detention time= 216.2 min calculated for 912 cf(100% of inflow) Center-of-Mass det. time= 216.2 min ( 1,004.0- 787.9 ) 505 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr 9"Storm Rainfall=1.00" Prepared by Microsoft Printed 8/29/2019 HydroCAD® 10.00-13 sln 00401 02014 HydroCAD Software Solutions LLC Page 10 Volume Invert Avall.Storage Storage Description #1A 162.50' 249 cf 34.00'W x 18.00'L x 3.67'H Field A 2,244 cf Overall - 1,621 cf Embedded = 623 of x 40.0% Voids #2A 163.00' 1,084 cf retain_it 2.5' x 8 Inside#1 Inside= 84.0"W x 30.0"H => 17.56 sf x 8.001 = 140.4 cf Outside= 96.0"W x 38.0"H => 25.33 sf x 8.001 = 202.7 cf 4 Rows adjusted for 39.6 cf perimeter wall 1,333 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 163.50' 12.0" Round Culvert L= 23.0' Ke= 0.500 Inlet/ Outlet Invert= 163.50' 1 158.32' S= 0.2252 '1' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 163.50' 4.0"Vert. Orifice/Grate C= 0.600 #3 Device 1 164.30' 6.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 165.20' 12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #5 Discarded 162.50' 1.020 inlhr Exfiltration over Surface area Phase-In= 0.01' Qlscarded OutFlow Max=0.01 cfs @ 11.30 hrs HW=162.54' (Free Discharge) S=Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max=0.01 cfs @ 12.93 hrs HW=163.57' TW=0.00' (Dynamic Tallwater) t =Culvert (Passes 0.01 cfs of 0.02 cfs potential flow) 2=OrificelGrate (Orifice Controls 0.01 cfs @ 0.91 fps) 3=OrificelGrate ( Controls 0.00 cfs) =OrificelGrate ( Controls 0.00 cfs) Summary for Pond 4P. Detention System 1 Inflow Area = 43,305 sf, 92.68% Impervious, Inflow Depth = 0.37" for 1" Storm event Inflow - 0.43 cfs @ 12.09 hrs, Volume= 1,319 cf Outflow = 0.04 cfs @ 12.98 hrs, Volume= 1,196 cf, Atten= 90%, Lag= 53.3 min Primary - 0.04 cfs @ 12.98 hrs, Volume= 1,196 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 164.06' @ 12.98 hrs Surf.Area= 5,300 sf Storage= 683 cf Plug-Flow detention time= 313.5 min calculated for 1,196 cf(91% of inflow) Center-of-Mass det. time= 267.8 min ( 1,091.8- 824.0 ) Volume Invert Avail.Storage Storage Description #1A 163.90' 329 cf 106.00'W x 50.001 x 2.67'H Field A 14,133 cf Overall - 13,312 of Embedded = 821 of x 40.0% Voids #2A 163.90' 8,530 cf retain_it 2.0' x 78 Inside#1 Inside= 84.0"W x 24.0"H => 13.78 sf x 8.00'L = 110.3 of Outside= 96.0"W x 32.0"H => 21.33 sf x 8.001 = 170.7 cf _ 13 Rows adjusted for 71.8 cf perimeter wall 8,859 cf Total Available Storage I 505 Sutton Proposed Conditions Hydrologic Analysis Type 1/124-hr 9"Storm Rainfall=1.00" Prepared by Microsoft Printed 8/29/2019 H droCADO 10.00-13 s/n 00401 ©2014 H droCAD Software Solutions LLC Page 11 Storage Group A created with Chamber Wizard Device Routing___ Invert Outlet Devices _ #1 Primary 159.00' 12.0" Round Culvert L= 34.0' Ke= 0.500 Inlet/Outlet Invert= 159.00'/ 158.32' S= 0.0200 T Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 163.90' 3.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 164.30' 8.0" W x 2.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 165.60' 4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Primary OutFlow Max=0.04 cfs @ 12.98 hrs HW=164.06' TW=0.00' (Dynamic Tailwater) t- =Culvert (Passes 0.04 cfs of 8.07 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.04 cfs @ 1.34 fps) 3=Orifice/Grate ( Controls 0.00 cfs) =Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Pond 5P. Infiltration System 4 Inflow Area = 15,214 sf,100.00% Impervious, Inflow Depth = 0.79" for 1" Storm event Inflow = 0.31 cfs @ 12.08 hrs, Volume= 1,003 cf Outflow = 0.05 cfs @ 11.86 hrs, Volume= 1,003 cf, Atten= 84%, Lag= 0.0 min Discarded = 0.05 cfs @ 11.86 hrs, Volume= 1,003 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 165.84' @ 12.56 hrs Surf.Area= 2,116 sf Storage= 287 cf Plug-Flow detention time= 35.3 min calculated for 1,003 cf (100% of inflow) Center-of-Mass det. time= 35.3 min ( 823.2 - 787.9 ) Volume Invert Avaii.Stora e Storage Description #1 165.50' 635 cf Custom Stage Data (Prismatic)Listed below (Recalc) 6,708 cf Overall - 5,120 of Embedded = 1,588 cf x 40.0% Voids #2 166.00' 3,308 cf retain_it 2.0' x 30 Inside#1 Inside= 84.0"W x 24.0"H => 13.78 sf x 8.001 = 110.3 cf Outside= 96.0"W x 32.0"H => 21.33 sf x 8.00'L = 170.7 cf 3,943 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store feet s -ft cubic-feet cubic-feet 165.50 2,116 0 0 168.67 2,116 6,708 6,708 505 Sutton Proposed Conditions Hydrologic Analysis Type III 24-hr ?"Storm Rainfall=9.00" Prepared by Microsoft Printed 8/29/2019 H droCADO 10.00-13 sin 00401 ©2014 H droCAD Software Solutions LLC Page 12 Device Routing Invert Outlet Devices #1 Primary 165.40' 12.0" Round Culvert L= 30.0' Ke= 0.500 Inlet 1 Outlet Invert= 165.40' 1 164.95' S= 0.0150 T Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 167.00' 12.0"W x 3.0" H Vert. Ori€icefGrate C= 0.600 #3 Device 1 167.80' 9.0"Vert. Orifice/Grate C= 0.600 #4 Device 1 168.00' 4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 #5 Discarded 165.50' 1.020 in/hr Exfiltration over Surface area Phase-In= 0.01' Qiscarded OutFlow Max=0.05 cfs @ 11.86 hrs HW=165.53' (Free Discharge) 5=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=165.50' TW=163.90' (Dynamic Tailwater) "C--1=Culvert (Passes 0.00 cfs of 0.04 cfs potential flow) 2=Orifice/Grate ( Controls 0.00 cfs) 3=OrificelGrate ( Controls 0.00 cfs) =Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Pond 6P: Infiltration Trench [87] Warning: Oscillations may require smaller dt or Finer Routing (severity=42) Inflow Area = 2,552 sf,100.00% Impervious, Inflow Depth = 0.79" for 1" Storm event Inflow 0.05 cfs @ 12.08 hrs, Volume= 168 cf Outflow - 0.01 cfs @ 12.55 hrs, Volume 168 cf, Atten= 83%, Lag= 27.9 min Discarded = 0.01 cfs @ 12.54 hrs, Volume= 167 of Primary = 0.00 cfs @ 12.55 hrs, Volume= 1 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 170,50' @ 12.55 hrs Surf.Area= 232 sf Storage= 70 cf Plug-Flow detention time= 214.0 min calculated for 168 cf (100% of inflow) Center-of-Mass det. time= 214.0 min ( 1,001.9 - 787.9 ) Volume Invert Avail.Storage Storage Description #1 169.00' 70 cf Stone Trench (Prismatic)Listed below (Recalc) 174 cf Overall x 40.0% Voids #2 170.50' 12 cf Area Over Trench (Prismatic)Listed below (Recalc) 81 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) s -ft cubic-feet cubic-feet 169.00 116 0 0 170.50 116 174 174 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 170.50 116 0 0 170.60 116 12 12 505 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr I"Storm Rainfall=9.00" Prepared by Microsoft Printed 8/2912019 HydroCADO 10,00-13 s/n 00401 O 2014 HydroCAD Software Solutions L.L.0 Page 13 Device Routing Invert Outlet Devices #1 Primary 170.50' 70,0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #2 Discarded 169.00' 1.020 inlhr Exfiltration over Surface area Phase-In= 0.01' piscarded OutFlow Max=0.01 cfs @ 12.54 hrs. HW=170.50' (Free Discharge) Z.,_,2=Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max=0.00 cfs @ 12.55 hrs. HW=170.50' TW=0.00' (Dynamic Tailwater) t1=Broad-Crested Rectangular Weir (Weir Controls 0.00 cfs @ 0.07 fps) 505 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr 2-Year Rainfall=3.20" Prepared by Microsoft Printed 8/29/2019 HydroCAD® 10.00-13 s/n 00401 OO 2014 HydroCAD Software Solutions_LLC Page 14 Summary for Subcatchment PSI: Runoff = 1.89 cfs @ 12.08 hrs, Volume= 6,192 cf, Depth= 2.64" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Year Rainfall=3.20" Area (so CN Description 3,170 74 >75% Grass cover, Good, HSG C 23,273 98 Paved parking, HSG C 661 98 Roofs, HSG C 987 98 Unconnected pavement, HSG C 28,091 95 Weighted Average 3,170 . 11.28% Pervious Area 24,921 88.72% Impervious Area 987 3.96% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PSI0: Runoff = 0.99 cfs @ 12.08 hrs, Volume= 3,423 cf, Depths 2.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Year Rainfall=3.20" Area (sf) CN Description 13,844 98 Roofs, HSG C 13,844 100.00% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlft ft/sec cfs 6.0 Direct Entry, Summary for Subcatchment PSI1: Runoff — 1.08 cfs @ 12.08 hrs, Volume= 3,762 cf, Depth= 2.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type Ill 24-hr 2-Year Rainfall=3.20" Area (sf) CN Description 15,214 98 Roofs, HSG C 15,214 100.00% Impervious Area I 505 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr 2-Year Rainfall=3.20" Prepared by Microsoft Printed 8/29/2019 H droCAD® 10.00-13 s/n 00401 ©2014 H droCAD Software Solutions LLC Page 15 Tc Length Slope Velocity Capacity Description min feet ftlft ft/sec cfs 6.0 Direct Entry, Summary for Subcatchment PSI 2: Runoff - 0.34 cfs @ 12.10 hrs, Volume= 1,109 cf, Depth= 1.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Year Rainfall=3.20" Area (sf) CN Description 12,822 74 >75% Grass cover, Good, HSG C 12,822 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 6.0 Direct Entry, Summary for Subcatchment PS2: Runoff - 0.90 cfs @ 12.08 hrs, Volume= 2,918 cf, Depth= 2.54" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Year Rainfall=3.20" Areas CN Description 2,572 74 >75% Grass cover, Good, HSG C 6,226 98 Paved parking, HSG C 1,474 98 Roofs, HSG C 3,495 98 Unconnected pavement, HSG C 13,767 94 Weighted Average 2,572 18.68% Pervious Area 11,195 81.32% Impervious Area 3,496 31.22% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) _(ftlft) (ftlsec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS3: Runoff = 0.52 cfs @ 12.09 hrs, Volume= 1,626 cf, Depth= 2.26" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Year Rainfall=3.20" 505 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr 2-Year Rainfall=3.20" Prepared by Microsoft Printed 8/29/2019 HydroCAD® 10.00-13 sln 00401 ©2014 HydroCAD Software Solutions LLC Page 16 Areas CN Description 2,355 74 >75% Grass cover, Good, HSG C 5,874 98 Paved parking, HSG C 34 98 Roofs, HSG C 378 98 Unconnected pavement, HSG C 8,641 91 Weighted Average 2,355 27.25% Pervious Area 6,286 72.75% Impervious Area 378 6.01% Unconnected Tc Length Slope Velocity Capacity Description min feet ftlft fUsec cfs 6.0 Direct Entry, Summary for Subcatchment PS4: Runoff = 0.45 cfs @ 12.09 hrs, Volume= 1,393 cf, Depth= 1.40" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 cars, dt= 0.01 hrs Type III 24-hr 2-Year Rainfall=3.20" Area (so CN Description 8,762 74 >75% Grass cover, Good, HSG C 3,160 98 Paved parking, HSG C 11,922 80 Weighted Average 8,762 73.49% Pervious Area 3,160 26.51% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ftlsec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PSS: Runoff - 0.62 cfs @ 12.09 hrs, Volume= 1,918 cf, Depth= 2.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Year Rainfall=3.20" Areas CN Description 4,846 74 >75% Grass cover, Good, HSG C 5,452 98 Paved parking, HSG C 95 98 Roofs, HSG C 1,133 98 Unconnected pavement, HSG C 11,526 88 Weighted Average 4,846 42.04% Pervious Area 6,680 57.96% Impervious Area 1,133 16.96% Unconnected 1 505 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr 2-Year Rainfal1M3,20" Prepared by Microsoft Printed 8/29/2019 H droCAD® 10.00-13 sln 00401 O 2014 H droCAD Software Solutions LLC Page 17 Tc Length Slope Velocity Capacity Description min feet ftlft) (fUsec) (cfs 6.0 Direct Entry, Summary for Subcatchment PS6: Runoff 0.14 cfs @ 12.10 hrs, Volume= 462 cf, Depth= 1.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0,01 hrs Type III 24-hr 2-Year Rainfall=3.20" Area (so CN Description 5,343 74 >75% Grass cover, Good, HSG C 5,343 100.00% Pervious Area Te Length Slope Velocity Capacity Description min feet ftlft) (fUsec) (cfs 6.0 Direct Entry, Summary for Subcatchment PS7: Runoff 0.07 cfs @ 12.10 hrs, Volume= 231 cf, Depth= 1.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Year Rainfall=3.20" Areas CN Description 2,666 74 >75% Grass cover, Good, HSG C 2,666 100,00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (fUsec) (cfs) 6.0 Direct Entry,. Summary for Subcatchment PS8: Runoff - 0.55 cfs @ 12.10 hrs, Volume= 1,807 cf, Depth= 1.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Year Rainfall=3.20" Area (sf) CN Description 20,900 74 >75% Grass cover, Good HSG C 20,900 100.00% Pervious Area 505 Sutton Proposed Conditions Hydrologic Analysis Type If! 24-hr 2-Year Rainfall=3.20" Prepared by Microsoft Printed 8/29/2019 H droCADO 10.00-13 sin 00401 0 2014 H droCAD Software Solutions LLC Page 18 Te Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 4.9 50 0.0300 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 1.3 210 0.0290 2.74 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.0 20 0.3500 9.52 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 6.2 280 Total Summary for Subcatchment PS8A: Runoff - 0.18 cfs @ 12.08 hrs, Volume= 631 cf, Depth= 2.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Year Rainfall=3.20" Area (sD CN Description 587 98 Roofs, HSG C 1,965 98 Unconnected pavement, HSG C 2,562 98 Weighted Average 2,552 100.00% Impervious Area 1,965 77.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft} (ftlsec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS9: Runoff - 1.28 cfs @ 12.08 hrs, Volume= 4,442 cf, Depth= 2.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Year Rainfall=3.20" Area (so CN Description 17,961 98 Roofs, HSG C 17,961 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ftlsec) (cfs) 6.0 Direct Entry, Summary for Reach DP1: [40] Hint: Not Described (Outflow=I nf low) Inflow Area = 126,309 sf, 78.59% Impervious, Inflow Depth > 1.60" for 2-Year event Inflow - 2.86 cfs @ 12.14 hrs, Volume= 16,876 of Outflow - 2.86 cfs @ 12.14 hrs, Volume= 16,876 cf, Atten= 0%, Lag= 0.0 min 505 Sutton Proposed Conditions Hydrologic Analysis Type !Il 24-hr 2-Year Rainfall=3.20" Prepared by Microsoft Printed 8/29/2019 HydroCAD® 10.00-13 s/n 00401 0 2014 HydroCAD Software Solutions LLC Page 19 Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Summary for Reach DP2: [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 23,452 sf, 10.88% Impervious, Inflow Depth = 1.09" for 2-Year event Inflow - 0.72 cfs @ 12.09 hrs, Volume= 2,127 cf Outflow - 0.72 cfs @ 12.09 hrs, Volume= 2,127 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Summary for Reach DP3: [40] Hint: Not Described (Outflow=I nf low) Summary for Reach DP4: [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 12,822 sf, 0.00% Impervious, Inflow Depth = 1.04" for 2-Year event Inflow = 0.34 cfs @ 12.10 hrs, Volume= 1,109 cf Outflow - 0.34 cfs @ 12.10 hrs, Volume= 1,109 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Summary for Reach DP5: [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 2,666 sf, 0.00% Impervious, Inflow Depth = 1.04" for 2-Year event Inflow = 0.07 cfs @ 12.10 hrs, Volume= 231 cf Outflow - 0.07 cfs @ 12.10 hrs, Volume= 231 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Summary for Pond 1 P: Retain It Inflow Area = 31,945 sf, 75.90% Impervious, Inflow Depth = 2.45" for 2-Year event Inflow = 1.94 cfs @ 12.09 hrs, Volume= 6,530 cf Outflow - 0.91 cfs @ 12.25 hrs, Volume= 6,530 cf, Atten= 53%, Lag= 9.9 min Discarded = 0.03 cfs @ 8.97 hrs, Volume= 2,439 cf Primary - 0.88 cfs @ 12.25 hrs, Volume= 4,090 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 505 Sutton Proposed Conditions Hydrologic Analysis Type fll 24-hr 2-Year Rainfall=3.20" Prepared by Microsoft Printed 8/29/2019 HydroCAD® 10.00-13 s/n 00401 ©2014 HydroCAD Software Solutions LLC Page 20 Peak Elev= 163.61' @ 12.25 hrs Surf.Area= 1,460 sf Storage= 1,502 cf Plug-Flow detention time= 54.4 min calculated for 6,528 cf (100% of inflow) Center-of-Mass det. time= 54.4 min ( 829.7- 775.4 ) Volume Invert Avail.Storage Storage Description #1A 162.00' 867 cf 146.00'W x 10.001 x 5.1TH Field A 7,543 cf Overall - 5,376 cf Embedded = 2,167 cf x 40.0% Voids #2A 162.50' 3,870 cf retain it 4.0' x 18 Inside#1 Inside= 84.0"W x 48.0"H => 28.87 sf x 8.00'L = 230.9 cf Outside= 96.0"W x 56.0"H => 37.33 sf x 8.001 = 298.7 cf 18 Rows adjusted for 286.9 cf perimeter wall 4,737 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 162.50' 12.0" Round Culvert L= 112.0' Ke= 0.500 Inlet 1 Outlet Invert= 162.50' / 153,84' S= 0.0773 '1' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 162.50' 6.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 164.50' 3.0"Vert. 0rifice1Grate C= 0.600 #4 Device 1 166.40' 12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #5 Discarded 162.00' 1.020 inlhr Exfiltration over Surface area Phase-In= 0.01' Discarded OutFlow Max=0.03 cfs @ 8.97 hrs HW=162.05' (Free Discharge) t5=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.88 cfs @ 12.25 hrs HW=163.61' TW=0.00' (Dynamic Tailwater) L1=Culvert (Passes 0.88 cfs of 2.95 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.88 cfs @ 4.46 fps) 3=Orifice/Grate ( Controls 0.00 cfs) =OrificeiGrate ( Controls 0.00 cfs) Summary for Pond 2P: Retain It Inflow Area = 13,767 sf, 81.32% Impervious, Inflow Depth = 2.54" for 2-Year event Inflow = 0.90 cfs @ 12.08 hrs, Volume= 2,918 of Outflow - 0.33 cfs @ 12.33 hrs, Volume= 2,918 cf, Atten= 63%, Lag= 15.0 min Discarded = 0.02 cfs @ 9.85 hrs, Volume= 1,551 cf Primary 0.31 cfs @ 12.33 hrs, Volume= 1,368 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 163.62' @ 12.33 hrs Surf.Area= 900 sf Storage= 977 cf Plug-Flow detention time= 136.7 min calculated for 2,918 cf(100% of inflow) Center-of-Mass det. time= 136.7 min ( 923.8 - 787.1 ) 505 Sutton Proposed Conditions Hydrologic Analysis Type !II 24-hr 2-Year Rainfall=3.20" Prepared by Microsoft Printed 8/29/2019 HydroCA_D® 10.00-13 sin 00401 0 2014 HydraCAD Software Solutions LLC Page 21 Volume Invert Avaii.Storage Storage Description #1A 162.00' 400 cf 50.00'W x 18.001 x 4.67'H Meld A 4,200 cf Overall - 3,200 cf Embedded = 1,000 cf x 40.0% Voids #2A 162,50' 2,311 cf retain it 3.5' x 12 Inside 41 Inside= 84.0"W x 42.0"H => 25.10 sf x 8.00'L = 200.8 cf Outside= 96.0"W x 50.0"H => 33.33 sf x 8.001 = 266.7 of 6 Rows adjusted for 98.2 cf perimeter wall 2,711 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 162.50' 12.0" Round Culvert L= 23.0' Ke= 0.500 Inlet/Outlet Invert= 162.50' 1 158.32' S= 0.1817 '1' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 162.90' 4.0"Vert. Orifice/Grate C= 0.600 #3 Device 1 163.80' 3.0"Vert. Orifice/Grate C= 0.600 #4 Device 1 164.80' 4.0" Vert, Orifice/Grate C= 0.600 #5 Device 1 165.40' 12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #6 Discarded 162,00' 1.020 inthr Exfiltration over Surface area Phase-In= 0.01' tscarded OutFlow Max=0.02 cfs @ 9.85 hrs HW=162.05' (Free Discharge) =Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.31 cfs @ 12.33 hrs HW=163.62' TW=0.00' (Dynamic Tallwater) l:�2=Orif ulvert (Passes 0.31 cfs of 2.97 cfs potential flow) icelGrate (Orifice Controls 0.31 cfs @ 3.57 fps) 3=OriflcelGrate ( Controls 0.00 cfs) =OrlflcelGrate ( Controls 0.00 cfs) S=OrificelGrate ( Controls 0.00 cfs) Summary for Pond 3P: Retain It Inflow Area = 13,844 sf,100.00% Impervious, Inflow Depth = 2.97" for 2-Year event Inflow - 0.99 cfs @ 12.08 hrs, Volume= 3,423 cf Outflow 0.65 cfs @ 12.17 hrs, Volume= 3,423 cf, A#ten= 34%, Lag= 5.3 min Discarded = 0.01 cfs @ 7.41 hrs, Volume= 1,353 of Primary = 0.63 cfs @ 12.17 hrs, Volume= 2,071 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peale Elev= 164.60' @ 12.17 hrs Surf.Area= 612 sf Storage= 879 cf Plug-Flow detention time= 117.4 min calculated for 3,423 cf(100% of inflow) Center-of-Mass det. time= 117.4 min ( 873.8 - 756.4 ) 505 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr 2-Year Rainfall=3.20" Prepared by Microsoft Printed 8/29/2019 HydroCADO 10.00-13 s{n 00401 0 2014 HydroCAD Software Solutions LLC Page 22 Volume Invert Avail.Storage Storage Description #1A 162.50' 249 of 34.00'W x 18.00'L x 3.67'H Field A 2,244 of Overall - 1,621 of Embedded = 623 of x 40.0% Voids #2A 163,00' 1,084 of retain_it 2.5' x 8 Inside#1 Inside= 84.0"W x 30.0"H => 17.56 sf x 8.001 = 140.4 cf Outside= 96.0"W x 38.0"H => 25.33 sf x 8.001 = 202.7 of 4 Rows adjusted for 39.6 of perimeter wall 1,333 of Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 163.50' 12.0" Round Culvert L= 23.0' Ke= 0.500 Inlet 1 Outlet Invert= 163.50' 1 158.32' S= 0.2252 ? Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 163.50' 4.0"Vert. Orifice/Grate C= 0.600 #3 Device 1 164.30' 6.0"Vert. OrlficelGrate C= 0.600 #4 Device 1 165.20' 12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #5 Discarded 162.50' 1.020 inlhr Exflltratlon over Surface area Phasedn= 0.01' Discarded OutFlow Max=0.01 cfs @ 7.41 hrs HW=162.54' (Free Discharge) t5=Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max=0.63 cfs @ 12.17 hrs HW=164.60' TW=0.00' (Dynamic Taiiwater) t--E=Culvert (Passes 0.63 cfs of 2.92 cfs potential flow) =Orifice/Grate (Orifice Controls 0.41 cfs @ 4.65 fps) =OrificelGrate (Orifice Controls 0.23 cfs @ 1.86 fps) =OrlficelGrate (Controls 0.00 cfs) Summary for Pond 4P: Detention System 1 Inflow Area = 43,305 sf, 92.68% Impervious, Inflow Depth = 1.72" for 2-Year event Inflow = 1.89 cfs @ 12.08 hrs, Volume= 6,192 cf Outflow - 0.40 cfs @ 12.50 hrs, Volume= 6,037 of, Atten= 79%, Lag= 25.0 min Primary = 0.40 cfs @ 12.50 hrs, Volume= 6,037 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 164.56' @ 12.50 hrs Surf.Area= 5,300 sf Storage= 2,908 of Plug-Flow detention time= 200.3min calculated for 6,035 of (97% of inflow) Center-of-Mass det. time= 185.2 min ( 966.1 - 781.0 ) Volume Invert Avail.Stora e Storage Description #1A 163.90' 329 of 106.00'W x 50.00'L x 2.67'H Field A 14,133 of Overall - 13,312 cf Embedded = 821 of x 40.0% Voids #2A 163.90' 8,530 of retain_it 2.0' x 78 Inside#1 Inside= 84.0"W x 24.0"H => 13.78 sf x 8.001 = 110.3 of Outside= 96.0"W x 32.0"H => 21.33 sf x 8.001 = 170.7 of 13 Rows adjusted for 71.8 of perimeter wall 8,859 cf Total Available Storage 505 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr 2-Year Rainfall=3.20" Prepared by Microsoft Printed 8/29/2019 HydroCAD® 10.00-13 s/n 00401 ©2014 HydroCAD Software Solutions LLC Page 23 Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 159.00' 12.0" Round Culvert L= 34.0' Ke= 0.500 Inlet 1 Outlet Invert= 159.00' 1 158.32' S= 0.0200 T Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 163.90' 3.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 164.30' 8.0" W x 2.0" H Vert. OrificelGrate C= 0.600 #4 Device 1 165.60' 4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Primary OutFlow Max=0.40 cfs @ 12.50 hrs HW=164.56' TW=0.00' (Dynamic Tailwater) t1=Culvert (Passes 0.40 cfs of 8.51 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.17 cfs @ 3.53 fps) 3=Orifice/Grate (Orifice Controls 0.22 cfs @ 2.02 fps) =Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Pond 5P: Infiltration System 4 Inflow Area = 15,214 sf,100.00% Impervious, Inflow Depth = 2.97" for 2-Year event Inflow - 1.08 cfs @ 12.08 hrs, Volume= 3,762 cf Outflow = 0.05 cfs @ 10.66 hrs, Volume= 3,762 cf, Atten= 95%, Lag= 0.0 min Discarded = 0.05 cfs @ 10.66 hrs, Volume= 3,762 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Dyn-Star-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 166.78' @ 14.48 hrs Surf.Area= 2,116 sf Storage= 1,766 cf Plug-Flow detention time= 296.2 min calculated for 3,762 cf (100% of inflow) Canter-of-Mass det. time= 296.2 min ( 1,052.6 - 756.4 ) Volume _Invert Avail.Storage Storage Description #1 165.50' 635 cf Custom Stage Data (Prismatic)Listed below (Recalc) 6,708 cf Overall - 5,120 cf Embedded = 1,588 cf x 40.0% Voids #2 166.00' 3,308 cf retain it 2.0' x 30 Inside#1 Inside= 84.0"W x 24.0"H => 13.78 sf x 8.001 = 110.3 cf Outside= 96.0"W x 32.0"H => 21.33 sf x 8.001 = 170.7 cf 3,943 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 165.50 2,116 0 0 168.67 2,116 6,708 6,708 505 Sutton Proposed Conditions Hydrologic Analysis Type fff 24-hr 2-Year Rainfaff=3.20" Prepared by Microsoft Printed 8/29/2019 HydroCADO 10.00-13 sin 00401 @ 2014 HydroCAD Software Solutions LLC Page 24 Device Routing Invert Outlet Devices #1 Primary 165.40' 12.0" Round Culvert L= 30.0' Ke= 0.500 ^ Inlet/ Outlet Invert= 165.40'1 164,95' S= 0.0150 T Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 167.00' 12.0"W x 3.0" H Vert, Orifice/Grate C= 0.600 #3 Device 1 167.80' 9.0"Vert. Orifice/Grate C= 0.600 #4 Device 1 168.00' 4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 #5 Discarded 165.50' 1.020 infhr Exfiltration over Surface area Phase-ln= 0.01' Discarded OutFlow Max=0.05 cfs @ 10.66 hrs HW=165.53' (Free Discharge) t--5=Exfiltration _(E=xfiltration Controls 0.05 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=165.50' TW=163.90' (Dynamic Tailwater) =Culvert (Passes 0.00 cfs of 0.04 cfs potential flow) 2=OrificelGrate ( Controls 0.00 cfs) 3=Orifice/Grate ( Controls 0.00 cfs) =Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Pond 6P: Infiltration Trench Inflow Area = 2,552 sf,100.00% Impervious, Inflow Depth = 2.97" for 2-Year event Inflow - 0.18 cfs @ 12.08 hrs, Volume= 631 cf Outflow = 0.18 cfs @ 12.08 hrs, Volume= 631 cf, Atten= 0%, Lag= 0.1 ruin Discarded 0.01 cfs @ 11.32 hrs, Volume= 311 cf Primary - 0.18 cfs @ 12.08 hrs, Volume= 320 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 170.51' @ 12.08 hrs Surf.Area= 232 sf Storage= 71 of Plug-Flow detention time= 108.0 min calculated for 631 cf(100% of inflow) Center-of-Mass det. time= 108.1 min ( 864.5- 756.4 ) Volume Invert Avail.Storage Storage Description #1 169.00' 70 cf Stone Trench (Prismatic)Listed below (Recalc) 174 cf Overall x 40.0% Voids #2 170.50' 12 cf Area Over Trench Prismatic Listed below Recalc 81 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 169.00 116 0 0 170.50 116 174 174 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 170.50 116 0 0 170.60 116 12 12 505 Sutton Proposed Conditions Hydrologic Analysis Type /I124-hr 2-Year Rainfafl=3.20" Prepared by Microsoft Printed 8/29/2019 H droCAD® 10,00-13 s/n 00401 OO 2014 H droCAD Software Solutions LLC Page 25 Device Routing Invert Outlet Devices #1 Primary 170.50' 70.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #2 Discarded 169.00' 1.020 inlhr Exfiltration over Surface area Phase-In= 0.01' Discarded OutFlow Max=0.01 cfs @ 11.32 hrs HW=170,50' (Free Discharge) t--2=Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutF'low Max=0.18 cfs @ 12.08 hrs HW=170.51' TW=0.00' (Dynamic Tailwater) L1=Broad-Crested Rectangular Weir (Weir Controls 0.18 cfs @ 0.26 fps) 505 Sutton Proposed Conditions Hydrologic Analysis Type Ill 24-hr 10-Year Rainfall=4.80" Prepares[ by Microsoft Printed 8/29/2019 HydroCAD® 10.00-13 s/n 00401 ®2014 HydroCAD Software Solutions LLC Page 26 Summary for Subcatchment PSI: Runoff = 2.94 cfs @ 12.08 hrs, Volume= 9,882 cf, Depth= 4.22" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Year Rainfall=4.80" Area (sf) CN Description 3,170 74 >75% Grass cover, Good, HSG C 23,273 98 Paved parking, HSG C 661 98 Roofs, HSG C 987 98 Unconnected pavement, HSG C 28,091 95 Weighted Average 3,170 11.28% Pervious Area 24,921 88.72% Impervious Area 987 3.96% Unconnected Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 6.0 Direct Entry, Summary for Subcatchment PSI0: Runoff 1.49 cfs @ 12.08 hrs, Volume 5,265 cf, Depth= 4.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Year Rainfall=4.80" Area (so CN Description 13,844 98 Roofs, HSG C 13,844 100.00% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 6.0 Direct Entry, Summary for Subcatchment PSI 1: Runoff = 1.64 cfs @ 12.08 hrs, Volume= 5,786 cf, Depth= 4.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Year Rainfall=4.80" Area (sf) CN Description 15,214 98 Roofs, HSG C 15,214 100.00% Impervious Area 505 Sutton Proposed Conditions Hydrologic Analysis Type l!! 24-hr 10-Year Rainfall=4.80" Prepared by Microsoft Printed 8/29/2019 H droCAD® 10.00-13 sln 00401 OO 2014 H droCAD Software Solutions LLC Page 27 To Length Slope Velocity Capacity Description min feet ft/ft) (ft/sec) (cfs 6.0 Direct Entry, Summary for Subcatchment PS12: Runoff = 0.76 cfs @ 12.09 hrs, Volume= 2,357 cf, Depth= 2.21" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type 111 24-hr 10-Year Rainfall=4.80" Area (so CN Description 12,822 74 >75% Grass cover, Good, HSG C 12,822 100.00% Pervious Area To Length Slope Velocity Capacity Description min feet ft/ft) (ft/sec) (cfs 6.0 Direct Entry, Summary for Subcatchment PS2: Runoff = 1.42 cfs @ 12.08 hrs, Volume= 4,716 of, Depth= 4.11" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Year Rainfall=4.80" Area (sf) CN Description * 2,572 74 >75% Grass cover, Good, HSG C 6,226 98 Paved parking, HSG C 1,474 98 Roofs, HSG C 3,495 98 Unconnected pavement, HSG C 13,767 94 Weighted Average 2,572 18.68% Pervious Area 11,195 81.32% Impervious Area 3,495 31.22% Unconnected To Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS3: Runoff 0.85 cfs @ 12.08 hrs, Volume= 2,728 of, Depth= 3.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Year Rainfall=4.80" 505 Sutton Proposed Conditions Hydrologic Analysis Type 111 24-hr 90-Year Rainfall=4.80" Prepared by Microsoft Printed 8/29/2019 HydroCADO 10.00-13 sln 00401 O 2014 HydroCAD Software Solutions LLC Page 28 Area (so CN Description 2,355 74 >75% Grass cover, Good, HSG C 5,874 98 Paved parking, HSG C 34 98 Roofs, HSG C 378 98 Unconnected pavement, HSG C 8,641 91 Weighted Average 2,355 27.25% Pervious Area 6,286 72.75% Impervious Area 378 6.01% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ftlsec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS4: Runoff — 0.87 cfs @ 12.09 hrs, Volume= 2,701 of, Depth= 2.72" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Year Rainfall=4.80" Area (so CN Description _ 8,762 74 >75% Grass cover, Good, HSG C 3,160 98 Paved parking, HSG C 11,922 80 Weighted Average 8,762 73.49% Pervious Area 3,160 26.51% I mpervious Area Tc Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 6.0 Direct Entry, Summary for Subcatchment PS5: Runoff = 1.06 cfs @ 12.09 hrs, Volume= 3,342 cf, Depth= 3.48" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Year Rainfall=4.80" Area (sf) CN Description 4,846 74 >75% Grass cover, Good, HSG C 5,452 98 Paved parking, HSG C 95 98 Roofs, HSG C 1,133 98 Unconnected pavement, HSG C 11,526 88 Weighted Average 4,846 42.04% Pervious Area 6,680 57.96% Impervious Area 1,133 16.96% Unconnected 505 Sutton Proposed Conditions Hydrologic Analysis Type If! 24-hr 10-Year Rainfall=4.80" Prepared by Microsoft Printed 8/29/2019 H droCAD® 10.00-13 sln 00401 ®2014 H droCAD Software Solutions LLC Page 29 Tc Length Slope Velocity Capacity Description min feet ftlft) (ftlsec) (cfs 6.0 Direct Entry, Summary for Subcatchment PS6: Runoff = 0.32 cfs @ 12.09 hrs, Volume= 982 cf, Depth= 2.21" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Year Rainfall=4.80" Area (sf) CN Description 5,343 74 >75% Grass cover, Good, HSG C 5,343 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 6.0 Direct Entry, Summary for Subcatchment PS7: Runoff 0.16 cfs @ 12.09 hrs, Volume= 490 cf, Depth= 2.21" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Year Rainfall=4.80" Area (sf) CN Description 2,666 74 >75% Grass cover, Good, HSG C 2,666 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ftlsec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS8: Runoff - 1.22 cfs @ 12.09 hrs, Volume= 3,842 cf, Depth= 2,21" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Year Rainfall=4.80" Area (sf) CN Description 20,900 74 >75% Grass cover, Good HSG C 20,900 100.00% Pervious Area 505 Sutton Proposed Conditions Hydrologic Analysis Type 111 24-hr 10-Year Rainfall=4.80" Prepared by Microsoft Printed 8/29/2019 HydroCAD® 10.00-13 s/n 00401 cO 2014 HydroCAD Software Solutions LLC Page_30 Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ftlsec) (cfs) 4.9 50 0.0300 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 1.3 210 0.0290 2.74 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.0 20 0.3500 9.52 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 6.2 280 Total Summary for Subcatchment PSBA: Runoff 0.27 cfs @ 12.08 hrs, Volume= 971 cf, Depth= 4.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Year Rainfall=4.80" Areas CN Description 587 98 Roofs, HSG C 1,965 98 Unconnected pavement, HSG C 2,552 98 Weighted Average 2,552 100,00% Impervious Area 1,965 77.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ftlsec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS9: Runoff - 1.94 cfs @ 12.08 hrs, Volume= 6,830 cf, Depth= 4.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Year Rainfall=4.80" Area (so CN Description 17,961 98 Roofs HSG C 17,961 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ftlsec) (cfs) 6.0 Direct Entry, Summary for Reach DP1: (40] Hint: Not Described (Outflow=I nf low) Inflow Area = 126,309 sf, 78.59% Impervious, Inflow Depth > 2.96" for 10-Year event Inflow = 4.94 cfs @ 12.12 hrs, Volume= 31,196 cf Outflow - 4.94 cfs @ 12.12 hrs, Volume= 31,196 cf, Atten= 0%, Lag= 0.0 min 1 505 Sutton Proposed Conditions Hydrologic Analysis Type It/ 24-hr 10-Year Rainfall=4.80" Prepared by Microsoft Printed 8/29/2019 HydroCADO 10.00-13 sin 00401 ©2014 HydroCAD Software Solutions LLC Page 31 Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Summary for Reach DP2: [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 23,452 sf, 10.88% Impervious, Inflow Depth = 2,27" for 10-Year event Inflow - 1.49 cfs @ 12.09 hrs, Volume= 4,437 cf Outflow = 1.49 cfs @ 12.09 hrs, Volume= 4,437 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0,01 hrs f 3 Summary for Reach DP3: [40] Hint: Not Described (Outflow=inflow) Summary for Reach DP4: [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 12,822 sf, 0.00% Impervious, Inflow Depth = 2.21" for 10-Year event Inflow = 0.76 cfs @ 12.09 hrs, Volume= 2,357 cf Outflow = 0.76 cfs @ 12.09 hrs, Volume= 2,357 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs! 3 Summary for Reach DP5: [40) Hint: Not Described (Outflow=inflow) Inflow Area = 2,666 sf, 0.00% Impervious, Inflow Depth = 2.21" for 10-Year event Inflow - 0,16 cfs @ 12,09 hrs, Volume= 490 of Outflow = 0.16 cfs @ 12.09 hrs, Volume= 490 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Summary for Pond 1 P: Retain It Inflow Area = 31,945 sf, 75.90% Impervious, Inflow Depth = 3.96" for 10-Year event Inflow - 3.09 cfs @ 12.08 hrs, Volume= 10,540 cf Outflow = 1.26 cfs @ 12.30 hrs, Volume= 10,540 cf, Atten= 59%, Lag= 12.7 min Discarded = 0.03 cfs @ 7.39 hrs, Volume= 2,818 cf Primary = 1.23 cfs @ 12.30 hrs, Volume= 7,723 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 505 Sutton Proposed Conditions Hydrologic Analysis Type !ll 24-hr 10-Year Rainfall=4.80" Prepared by Microsoft Printed 8/29/2019 HydroCADO 10.00-13 sln 00401 ©2014 HydroCAD Software Solutions LLC Page 32 Peak Elev= 164.44' @ 12.30 hrs Surf.Area= 1,460 sf Storage= 2,404 cf Plug-Flow detention time= 49.4 min calculated for 10,537 cf(100% of inflow) Center-of-Mass det. time= 49.4 min ( 816.8 - 767.4 ) Volume Invert Avaii.Storage Storage Description #1A 162.00' 867 cf 146.00'W x 10.001 x 5.17'H Field A 7,543 cf Overall - 5,376 cf Embedded = 2,167 cf x 40.0% Voids #2A 162.50' 3,870 cf retain it 4.0' x 18 Inside#1 Inside= 84.0"W x 48.0"H => 28.87 sf x 8.001 = 230.9 cf Outside= 96.0"W x 56.0"H => 37.33 sf x 8.001 = 298.7 of 18 Rows adjusted for 286.9 cf perimeter wall 4,737 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices _ #1 Primary 162.50' 12.0" Round Culvert L= 112.0' Ke= 0.500 Inlet 1 Outlet Invert= 162.50' 1 153.84' S= 0.0773 7' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 162.50' 6.0" Vent. OrificelGrate C= 0.600 #3 Device 1 164.50' 3.0" Vert, OrificelGrate C= 0.600 #4 Device 1 166.40' 12.0" Horiz. OrificelGrate C= 0.600 Limited to weir flow at low heads #5 Discarded 162.00' 1.020 inlhr Exfiltration over Surface area Phase-In= 0.01' Discarded OutFlow Max=0.03 cfs @ 7.39 hrs HW=162.05' (Free Discharge) 't--5=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=1.23 cfs @ 12.30 hrs HW=164.44' TW=0.00' (Dynamic Tailwater) t-- =Culvert (Passes 1.23 cfs of 4.53 cfs potential flow) 2=OrificelGrate (Orifice Controls 1.23 cfs @ 6.25 fps) 3=OriflcelGrate ( Controls 0.00 cfs) =Orifice/Grate ( Controls 0.00 cfs) Summary for Pond 2P: Retain It Inflow Area = 13,767 sf, 81.32% Impervious, Inflow Depth = 4.11" for 10-Year event Inflow - 1.42 cfs @ 12.08 hrs, Volume= 4,716 cf Outflow = 0.62 cfs @ 12.27 hrs, Volume= 4,716 cf, Atten= 56%, Lag= 11.0 min Discarded = 0.02 cfs @ 8.48 hrs, Volume= 1,814 cf Primary - 0.60 cfs @ 12.27 hrs, Volume= 2,902 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 164.27' @ 12,27 hrs Surf.Area= 900 sf Storage= 1,443 of Plug-Flow detention time= 113.1 min calculated for 4,716 of (100% of inflow) Center-of-Mass det. time= 113.1 min ( 8877- 774.6 ) 505 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr 10-Year Rainfall=4.80" Prepared by Microsoft Printed 8/29/2019 H droCADO 10.00-13 sin 00401 OO 2014 H droCAD Software Solutions LLC Pa e 33 Volume Invert A�ail.Storage Storage Description - - #1A 162,00' 400 cf 50.00'W x 18.001 x 4.67H Field A 4,200 cf Overall - 3,200 cf Embedded = 1,000 cf x 40.0% Voids #2A 162.50' 2,311 cf retain it 3.5' x 12 Inside#1 Inside= 84.0"W x 42.0"H => 25.10 sf x 8.00'L W 200.8 cf Outside= 96.0"W x 50.0"H => 33.33 sf x 8.00'L = 266.7 cf 6 Rows adjusted for 98.2 cf perimeter wall 2,711 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 162,50' 12.0" Round Culvert L= 23.0' Ke= 0.500 Inlet/ Outlet Invert= 162.50' 1 158.32' S= 0.1817 '1' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 162.90' 4.0"Vert. Orifice/Grate C= 0.600 #3 Device 1 163.80' 3.0"Vert. Orifice/Grate C= 0.600 #4 Device 1 164.80' 4.0"Vert. Orifice/Grate C= 0.600 #5 Device 1 165,40' 12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #6 Discarded 162.00' 1.020 inlhr Exfiitration over Surface area Phase-In= 0.01' Discarded OutFlow Max=0.02 cfs @ 8.48 hrs HW=162.05' (Free Discharge) T 6=Exfiltration (Exfiitration Controls 0.02 cfs) Primary OutFlow Max=0.60 cfs @ 12.27 hrs HW=164.27' TW=0.00' (Dynamic Tailwater) L =Culvert (Passes 0.60 cfs of 4.26 cfs potential flow) 2=Orifice1Grate (Orifice Controls 0.46 cfs @ 5.28 fps) 3=OrificelGrate (Orifice Controls 0.14 cfs @ 2.83 fps) =OrificelGrate ( Controls 0.00 cfs) S=Orifice1Grate ( Controls 0.00 cfs) Summary for Pond 3P: Retain It Inflow Area = 13,844 sf,100.00% Impervious, Inflow Depth = 4.56" for 10-Year event Inflow - 1.49 cfs @ 12.08 hrs, Volume= 5,265 of Outflow = 1.10 cfs @ 12.15 hrs, Volume= 5,265 cf, Atten= 26%, Lag= 4.3 min Discarded = 0.01 cfs @ 5.27 hrs, Volume= 1,489 cf Primary = 1.09 cfs @ 12.15 hrs, Volume= 3,776 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 164.96' @ 12.15 hrs Surf.Area= 612 sf Storage= 1,053 cf Plug-Flow detention time= 92.4 min calculated for 5,263 cf(100% of inflow) Center-of-Mass stet. time= 92.5 min ( 841.2 - 748.7 ) 505 Sutton Proposed Conditions Hydrologic Analysis Type U/24-hr 10-Year Rainfafl=4.80" Prepared by Microsoft Printed 8/29/2019 H droCADO 10.00-13 s/n 00401 ©2014 H droCAD Software Solutions LLC Page 34 Volume Invert Avail.Storage Storage Description #1A 162.50' 249 cf 34.00'W x 18.00'L x 3.67'H Field A 2,244 cf Overall - 1,621 cf Embedded = 623 cf x 40.0% Voids #2A 163,00' 1,084 cf retain_it 2.5' x 8 Inside#1 Inside= 84.0"W x 30.0"H => 17.56 sf x 8.001 = 140.4 cf Outside= 96.0"W x 38.0"H => 25.33 sf x 8.001 = 202.7 cf 4 Rows adjusted for 39.6 cf perimeter wall 1,333 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 163.50' 12.0" Round Culvert L= 23.0' Ke= 0.500 Inlet/Outlet Invert= 163.50' / 158.32' S= 0.2252 T Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 163.50' 4.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 164.30' 6.0"Vert. Orifice/Grate C= 0.600 #4 Device 1 165.20' 12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #5 Discarded 162,50' 1.020 infhr Exfiltration over Surface area Phase-In= 0.01' Qiscarded OutFlow Max=0.01 cfs @ 5.27 hrs HW=162.54' (Free Discharge) S=Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max=1.09 cfs @ 12.15 hrs HW=164.96' TW=0.00' (Dynamic Tailwater) 1�--E=Culvert (Passes 1.09 cfs of 3.71 cfs potential flow) =Orifice/Grate (Orifice Controls 0.48 cfs @ 5.48 fps) =Orifice/Grate (Orifice Controls 0.61 cfs @ 3.10 fps) =Orifice/Grate ( Controls 0.00 cfs) Summary for Pond 4P. Detention System 1 Inflow Area = 43,305 sf, 92.68% Impervious, Inflow Depth = 3.03" for 10-Year event Inflow - 2.94 cfs @ 12.08 hrs, Volume= 10,919 cf Outflow = 0.63 cfs @ 12.61 hrs, Volume= 10,753 cf, Atten= 78%, Lag= 31.5 min Primary = 0.63 cfs @ 12.61 hrs, Volume= 10,753 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs/3 Peak Elev= 164.96' @ 12.61 hrs Surf.Area= 5,300 sf Storage= 4,644 cf Plug-Flow detention time= 166.0 min calculated for 10,753 cf(98% of inflow) Center-of-Mass det. time= 156.3 min ( 928.2 - 771.9 ) Volume Invert Avail.Storage Storage Description #1A 163.90' 329 cf 106.00'W x 60.00'L x 2.67'H Field A 14,133 of Overall - 13,312 cf Embedded = 821 cf x 40.0% Voids #2A 163,90' 8,530 cf retain_it 2.0' x 78 Inside#1 Inside= 84.0"W x 24.0"H => 13.78 sf x 8.001 = 110.3 cf Outside= 96.0"W x 32.0"H => 21.33 sf x 8.001 = 170.7 cf 13 Rows adjusted for 71.8 cf perimeter wall 8,859 cf Total Available Storage 505 Sutton Proposed Conditions Hydrologic Analysis Type /1124-hr 10-YearRainfal1=4,80" Prepared by Microsoft Printed 8/29/2019 HydroCADO 10.00-13 sln 00401 O 2014 HydroCAD Software Solutions LLC Page 35 Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 159.00' 12.0" Round Culvert L= 34.0' Ke= 0,500 Inlet/Outlet Invert= 159.00'1 158.32' S= 0.0200 T Cc= 0.900 n= 0,012, Flow Area= 0.79 sf #2 Device 1 163.90' 3.0"Vert. Orifice/Grate C= 0.600 #3 Device 1 164.30' 8.0"W x 2.0" H Vert, Orifice/Grate C= 0,600 #4 Device 1 165.60' 4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0,40 0.60 0,80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Primary OutFlow Max=0.63 cfs @ 12.61 hrs HW=164,96' TW=0.00' (Dynamic Tailwater) =Culvert (Passes 0.63 cfs of 8.84 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.23 cfs @ 4.65 fps) 3=Orifice/Grate (Orifice Controls 0.41 cfs @ 3.65 fps) =Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Pond 5P: Infiltration System 4 Inflow Area = 15,214 sf,100.00% Impervious, Inflow Depth = 4.56" for 10-Year event Inflow - 1.64 cfs @ 12.08 hrs, Volume= 5,786 of Outflow = 0.32 cfs @ 12.51 hrs, Volume= 5,786 of, Atten= 81%, Lag= 25.8 min Discarded = 0.05 cfs @ 9.32 hrs, Volume= 4,749 of Primary = 0.27 cfs @ 12.51 hrs, Volume= 1,037 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0,01 hrs/3 Peak Elev= 167.19' @ 12.51 hrs Surf.Area= 2,116 sf Storage= 2,488 of Plug-Flow detention time= 316.5 min calculated for 5,784 of (100% of inflow) Center-of-Mass det. time= 316.6 min ( 1,065.3 - 748.7 } Volume Invert Avail.Storage Storage Description #1 165,50 635 of Custom Stage Data (Prismatic)List,, el,_.......(Re Listed be low ow {Recalc) 6,708 of Overall - 5,120 of Embedded = 1,588 of x 40,0% Voids #2 166.00' 3,308 of retain it 2.0' x 30 Inside#1 Inside= 84.0"W x 24.0"H => 13.78 sf x 8.001 = 110.3 cf Outside= 96.0"W x 32.0"H => 21.33 sf x 8.00'L = 170.7 of 3,943 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet)_ (cubic-feet) 165.50 2,116 0 0 168.67 2,116 6,708 6,708 505 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr 90-Year Rainfall=4.80" Prepared by Microsoft Printed 8/29/2019 HydroCADO 10.00-13 sln 00401 C 2014 HydroCAD Software Solutions LLC Page 36 Device Routing Invert Outlet Devices #1 Primary 165.40' 12.0" Round Culvert L= 30.0' Ke= 0.500 Inlet/ Outlet Invert= 165.40'1164,95' S= 0.0150 'I' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 167.00' 12.0"W x 3.0" H Vert. OrificelGrate C= 0.600 #3 Device 1 167.80' 9.0"Vert:. Orifice/Grate C= 0.600 #4 Device 1 168.00' 4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 #5 Discarded 165.50' 1.020 inlhr Exfiltration over Surface area Phase-In= 0.01' Discarded OutFiow Max=0.05 cfs @ 9.32 hrs HW=165.53' (Free Discharge) t5=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=0.27 cfs @ 12.51 hrs HW=167.19' TW=164.95' (Dynamic Tailwater) tE=Culvert (Passes 0.27 cfs of 4.30 cfs potential flow) =OrificelGrate (Orifice Controls 0.27 cfs @ 1.40 fps) =OrificelGrate ( Controls 0.00 cfs) =Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Pond 6P: Infiltration Trench Inflow Area = 2,552 sf,100.00% Impervious, Inflow Depth = 4.56" for 10-Year event Inflow = 0.27 cfs @ 12.08 hrs, Volume= 971 cf Outflow = 0.27 cfs @ 12.08 hrs, Volume= 971 cf, Atten= 0%, Lag= 0.1 min Discarded = 0.01 cfs @ 9.96 hrs, Volume= 375 cf Primary - 0.27 cfs @ 12.08 hrs, Volume= 595 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peale Elev= 170.51' @ 12.08 hrs Surf.Area= 232 sf Storage= 71 cf Plug-Flow detention time= 82.2 min calculated for 970 cf(100% of inflow) Center-of-Mass det. time 82.3 min ( 831.0- 748.7 ) Volume Invert Avail.Storage Storage Description #1 169.00' 70 cf Stone Trench (Prismatic)Listed below (Recalc) 174 cf Overall x 40.0% Voids #2 170,50' 12 of Area Over Trench (Prismatic)Listed below_(Recalc 81 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet 169.00 116 0 0 170.50 116 174 174 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 170.50 116 0 0 170.60 116 12 12 505 Sutton Proposed Conditions Hydrologic Analysis Type Ill 24-hr 10-Year Rainfall=4.80" Prepared by Microsoft Printed 8/29/2019 HydroCADO 10.00-13 sln 00401 ©2014 HydroCAD Software Solutions LLC Page 37 Device Routing Invert Outlet Devices #1 Primary 170.50' 70.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #2 Discarded 169.00' 1.020 inlhr Exfiltration over Surface area Phase-In= 0.01' Qiscarded OutFlow Max=0.01 cfs @ 9.96 hrs HW=170.50' (Free Discharge) "r---2=E,xfiltration (E=xfiltration Controls 0.01 cfs) Primary OutFlow Max=0.27 cfs @ 12.08 hrs HW=170.51' TW=0.00' (Dynamic Tailwater) �1=Broad-Crested Rectangular Weir (Weir Controls 0.27 cfs @ 0.30 fps) 505 Sutton Proposed Conditions Hydrologic Analysis Type Ill 24-hr 25-Year Rainfall=6.00" Prepared by Microsoft Printed 8/29/2019 HydroCAD® 10.00-13 s/n 00401 ©2014 HydroCAD Software Solutions LLC Page 38 Summary for Subcatchment PSI: Runoff = 3.72 cfs @ 12.08 hrs, Volume= 12,668 cf, Depth= 5.41" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=6.00" Area (so CN Description 3,170 74 >75% Grass cover, Good, HSG C 23,273 98 Paved parking, HSG C 661 98 Roofs, HSG C 987 98 Unconnected pavement, HSG C 28,091 95 Weighted Average 3,170 11.28% Pervious Area 24,921 88.72% Impervious Area 987 3.96% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ftlsec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS10: Runoff = 1.87 cfs @ 12.08 hrs, Volume= 6,647 cf, Depth= 5.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=6.00" Areas CN Description 13,844 98 Roofs, HSG C 13,844 100,00% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlft ft/sec cfs 6.0 Direct Entry, Summary for Subcatchment PST[: Runoff - 2.05 cfs @ 12.08 hrs, Volume= 7,305 cf, Depth= 5.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=6.00" Area (so CN Description 15,214 98 Roofs, HSG C 15,214 100.00% Impervious Area 605 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr 25-Year Rainfall=6.00" Prepared by Microsoft Printed 8/29/2019 H droCAD® 10.00-13 s/n 00401 O 2014 H droCAD Software Solutions LLC Page 39 Tc Length Slope Velocity Capacity Description min feet ft/ft)- (ft/sec) (cfs 6.0 Direct Entry, Summary for Subcatchment PS12: Runoff 1.10 cfs @ 12.09 hrs, Volume= 3,403 cf, Depth= 3.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=6.00" Areas CN Description 12,822 74 >75% Grass cover, Good, HSG C 12,822 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 6.0 Direct Entry, Summary for Subcatchment PS2: Runoff 1.80 cfs @ 12.08 hrs, Volume= 6,077 cf, Depth= 5.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=6.00" Areas CN Description 2,572 74 >75% Grass cover, Good, HSG C 6,226 98 Paved parking, HSG C 1,474 98 Roofs, HSG C 3,495 98 Unconnected pavement, HSG C 13,767 94 Weighted Average 2,572 18.68% Pervious Area 11,195 81.32% Impervious Area 3,495 31.22% Unconnected Tc Length Slope Velocity Capacity Description min feet ft/ft ftlsec cfs 6.0 Direct Entry, Summary for Subcatchment PS3: Runoff = 1.09 cfs @ 12.08 hrs, Volume= 3,570 cf, Depth= 4.96" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=6.00" 505 Sutton Proposed Conditions Hydrologic Analysis Type I1124-hr 25-Year Rainfall=6.00" Prepared by Microsoft Printed 8/29/2019 HydroCAD® 10.00-13 s/n 00401 02014 HydroCAD Software Solutions LLC Page 40 Area (so CN Description 2,355 74 >75% Grass cover, Good, HSG C 5,874 98 Paved parking, HSG C 34 98 Roofs, HSG C 378 98 Unconnected pavement, HSG C 8,641 91 Weighted Average 2,355 27.25% Pervious Area 6,286 72.75% Impervious Area 378 6.01% Unconnected Tc Length Slope Velocity Capacity Description min feet ftlft) (ftlsec) (cfs 6.0 Direct Entry, Summary for Subcatchment PS4: Runoff - 1.21 cfs @ 12.09 hrs, Volume= 3,757 cf, Depth= 3.78" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=6.00" Area (so CN Description 8,762 74 >75% Grass cover, Good, HSG C 3,160 98 Paved parking, HSG C 11,922 80 Weighted Average 8,762 73.49% Pervious Area 3,160 26.51% Impervious Area Tc Length Slope Velocity Capacity Description min feet) fVft ftlsec cfs 6.0 Direct Entry, Summary for Subcatchment PS5: Runoff - 1.39 cfs @ 12.09 hrs, Volume= 4,443 cf, Depth= 4.63" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=6.00" Area (so CN Description 4,846 74 >75% Grass cover, Good, HSG C 5,452 98 Paved parking, HSG C 95 98 Roofs, HSG C 1,133 98 Unconnected pavement, HSG C 11,526 88. Weighted Average 4,846 42.04% Pervious Area 6,680 57.96% Impervious Area 1,133 16.96% Unconnected I 505 Sutton Proposed Conditions Hydrologic Analysis Type Ill 24-hr 25-Year Rainfall=6.00f, Prepared by Microsoft Printed 8/29/2019 H droCAD® 10.00-13 s/n 00401 ©2014 H droCAD Software Solutions LLC Page 41 Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 6.0 Direct Entry, Summary for Subcatchment PS6: Runoff 0.46 cfs @ 12.09 hrs, Volume= 1,418 cf, Depth= 3.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=6.00" Area (sf) _CN Description 5,343 74 >75% Grass cover, Good, HSG C 5,343 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft) (ftlsec) (cfs 6.0 Direct Entry, Summary for Subcatchment PS7: Runoff 0.23 cfs @ 12.09 hrs, Volume= 708 cf, Depth= 3.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=6.00" Areas CN Description 2,666 74 >75% Grass cover, Good, HSG C 2,666 100,00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 6.0 Direct Entry, Summary for Subcatchment PS8: Runoff - 1.78 cfs @ 12.09 hrs, Volume= 5,547 cf, Depth= 3.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36,00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=6.00" Area (sf) CN Description 20,900 74 >75% Grass cover, Good, HSG C 20,900 100.00% Pervious Area 505 Sutton Proposed Conditions Hydrologic Analysis Type 111 24-hr 25-Year Rainfall=6.00" Prepared by Microsoft Printed 8/29/2019 H droCAD® 10.00-13 sin 00401 O 2014 H droCAD Software Solutions LLC Page 42 Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 4.9 50 0.0300 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 1.3 210 0.0290 2.74 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.0 20 0.3500 9.52 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 6.2 280 Total: Summary for Subcatchment PS8A: Runoff = 0.34 cfs @ 12.08 hrs, Volume= 1,225 cf, Depth= 5.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=6.00" Area (sf) CN Description 587 98 Roofs, HSG C 1,965 98 Unconnected pavement, HSG C 2,552 98 Weighted Average 2,552 100.00% Impervious Area 1,965 77.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS9: Runoff = 2.42 cfs @ 12.08 hrs, Volume= 8,624 cf, Depth= 5.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=6.00" Area (sf) CN Description 17,961 98 Roofs, HSG C 17,961 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Reach DP1: [40j Hint: Not Described (Outflow=Inflow) Inflow Area = 126,309 sf, 78.59% Impervious, Inflow Depth a 4.07" for 25-Year event Inflow - 6.30 cfs @ 12.13 hrs, Volume= 42,803 cf Outflow = 6.30 cfs @ 12.13 hrs, Volume= 42,803 cf, Atten= 0%, Lag= 0.0 min i 505 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr 25-Year Rainfall=6.00" j Prepared by Microsoft Printed 8/29/2019 HydroCAD® 10,00-13 sln 00401 ©2014 Hyd_roCAD Software Solutions LLC Page 43 Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Summary for Reach DP2: [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 23,452 sf, 10.88% Impervious, Inflow Depth = 3.26" for 25-Year event Inflow 2.12 cfs @. 12.09 hrs, Volume= 6,362 cf Outflow - 2.12 cfs @ 12.09 hrs, Volume= 6,362 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Summary for Reach DP3: [40] Hint: Not Described (Outflow=lnflow) Summary for Reach DP4: [40] Hint: Not Described (Outflow=I nf low) Inflow Area = 12,822 sf, 0.00% Impervious, Inflow Depth = 3.18" for 25-Year event Inflow = 1.10 cfs @ 12.09 hrs, Volume= 3,403 cf Outflow - 1.10 cfs @ 12.09 hrs, Volume= 3,403 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Summary for Reach DP5: [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 2,666 sf, 0.00% Impervious, Inflow Depth = 3.18" for 25-Year event Inflow - 0.23 cfs @ 12.09 hrs, Volume= 708 cf Outflow = 0.23 cfs @ 12.09 hrs, Volume= 708 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Summary for Pond 1 P: Retain It Inflow Area = 31,945 sf, 75.90% Impervious, Inflow Depth = 5.11" for 25-Year event Inflow - 3.97 cfs @ 12.08 hrs, Volume= 13,612 cf Outflow = 1.63 cfs @ 12.29 hrs, Volume= 13,612 cf, Atten= 59%, Lag= 12.5 min Discarded = 0.03 cfs @ 6.41 hrs, Volume= 2,970 cf Primary = 1.59 cfs @ 12.29 hrs, Volume= 10,641 cf Routing by Dyn-Star-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 505 Sutton Proposed Conditions Hydrologic Analysis Type I1124-hr 25-Year Rainfall=6.00" Prepared by Microsoft Printed 8/29/2019 HydroCAD® 10.00-13 s/n 00401 ©2014 HydroCAD Software Solutions LLC Page 44 Peale Elev= 165.06' @ 12.29 hrs Surf.Area= 1,460 sf Storage= 3,082 cf Plug-Flow detention time= 45.8 min calculated for 13,608 cf(100% of inflow) Center-of-Mass det. time= 45.9 min ( 809.2 - 763.3 ) Volume Invert Avail.Storage Storage Description #1A 162.00' 867 cf 146.00'W x 10.001 x 5.17'H Field A 7,543 cf Overall - 5,376 cf Embedded = 2,167 cf x 40.0% Voids #2A 162.50' 3,870 cf retain it 4.0' x 18 Inside#1 Inside= 84.0"W x 48.0"H => 28.87 sf x 8.001 = 230.9 cf Outside= 96.0"W x 56.0"H => 37.33 sf x 8.001 = 298.7 cf 18 Rows adjusted for 286.9 cf perimeter wall 4,737 of Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices - #1 Primary 162.50' 12.0" Round Culvert L= 112.0' Ke= 0.500 Inlet/ Outlet Invert= 162.50' / 153.84' S= 0.0773 T Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 162.50' 6.0"Vert. Orifice/Grate C= 0.600 #3 Device 1 164.50' 3.0"Vert. Orifice/Grate C= 0.600 #4 Device 1 166.40' 12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #5 Discarded 162.00' 1.020 in/hr Exfiltration over Surface area Phase-In= 0.01' Qiscarded OutFlow Max=0.03 cfs @ 6.41 hrs HW=162.05' (Free Discharge) S=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=1.59 cfs @ 12.29 hrs HW=165.06' TW=0.00' (Dynamic Tailwater) L1=Culvert (Passes 1.59 cfs of 5.42 cfs potential flow) 2=OrificelGrate (Orifice Controls 1.44 cfs @ 7.31 fps) 3=Orifice/Grate (Orifice Controls 0.16 cfs @ 3.17 fps) Orifice/Grate ( Controls 0.00 cfs) Summary for Pond 2P: Retain It Inflow Area = 13,767 sf, 81.32% Impervious, Inflow Depth = 5.30" for 25-Year event Inflow 1.80 cfs @ 12.08 hrs, Volume= 6,077 cf Outflow - 0.77 cfs @ 12.27 hrs, Volume= 6,077 cf, Atten= 57%, Lag= 11.4 min Discarded = 0.02 cfs @ 7.53 hrs, Volume= 1,939 cf Primary - 0.75 cfs @ 12.27 hrs, Volume= 4,137 cf Routing by Dyn-Star-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs/3 Peale Elev= 164.71' @ 12.27 hrs Surf.Area= 900 sf Storage= 1,755 cf Plug-Flow detention time= 101.0 min calculated for 6,075 cf (100% of inflow) Center-of-Mass det. time= 101.0 min ( 86M- 768.5 ) i 505 Sutton Proposed Conditions Hydrologic Analysis Type fli 24-hr 25-Year Rainfaff=6.00 Prepared by Microsoft Printed 8/29/2019 H droCADO 10.00-13 sln 00401 ©2014 H droCAD Software Solutions LLC Page 45 Volume Invert Avail.Storage Storage Description #1A 162.00' 400 cf 50.00'W x 18.00'L x 4.67'H Field A 4,200 cf Overall - 3,200 cf Embedded = 1,000 cf x 40.0% Voids #2A 162.50' 2,311 cf retain it 3.5' x 12 Inside#1 Inside= 84.0"W x 42.0"H => 25.10 sf x 8.001 = 200.8 cf Outside= 96.0"W x 50.0"H => 33.33 sf x 8.00'L = 266.7 cf 6 Rows adjusted for 98.2 cf perimeter wall 2,711 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 162.50' 12.0" Round Culvert L= 23.0' Ke= 0.500 Inlet/ Outlet Invert= 162,50' 1 158,32' S= 0.1817 '1' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 162.90' 4.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 163.80' 3.0"Vert. Orifice/Grate C= 0.600 #4 Device 1 164.80' 4.0"Vert. Orifice/Grate C= 0.600 #5 Device 1 165,40' 12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #6 Discarded 162.00' 1.020 inlhr Exfiltration over Surface area Phase-In= 0.01' Discarded OutFlow Max=0.02 cfs @ 7.53 hrs HW=162.05' (Free Discharge) T 6=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.75 cfs @ 12.27 hrs HW=164.71' TW=0.00' (Dynamic Tailwater) t- =Culvert (Passes 0.75 cfs of 4.94 cfs potential flow) 2=OrificelGrate (Orifice Controls 0.54 cfs @ 6.17 fps) 3=OrificelGrate (Orifice Controls 0.21 cfs @ 4.26 fps) =OrificelGrate ( Controls 0.00 cfs) =0rifice1Grate ( Controls 0.00 cfs) Summary for Pond 3P: Retain It Inflow Area = 13,844 sf,100.00% Impervious, Inflow Depth = 5.76" for 25-Year event Inflow = 1.87 cfs @ 12.08 hrs, Volume= 6,647 cf Outflow = 1.43 cfs @ 12.15 hrs, Volume= 6,647 cf, Atten= 24%, Lag=4.0 min Discarded = 0.01 cfs @ 3.96 hrs, Volume= 1,534 cf Primary = 1.41 cfs @ 12.15 hrs, Volume= 5,114 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 165.25' @ 12.15 hrs Surf.Area= 612 sf Storage= 1,186 cf Plug-Flow detention time= 80.2 min calculated for 6,645 cf (100% of inflow) Center-of-Mass det. time= 80.3 min ( 825.4 - 745.1 ) 505 Sutton Proposed Conditions Hydrologic Analysis Type 11l 24-hr 25-Year Rainfall=6.00" Prepared by Microsoft Printed 8/29/2019 H droCADO 10.00-13 s/n 00401 ©2014 H droCAD Software Solutions LLC Page 46 Volume Invert Avail.Storage Storage Description #1A 162.50' 249 cf 34.00'W x 18.00%x 3.67'H Field A 2,244 cf Overall - 1,621 cf Embedded = 623 cf x 40.0% Voids #2A 163.00' 1,084 cf retain_it 2.5' x 8 Inside#1 Inside= 84.0"W x 30.0"H => 17.56 sf x 8.001 = 140.4 cf Outside= 96.0"W x 38.0"H => 25.33 sf x 8.001 = 202.7 cf 4 Rows adjusted for 39.6 cf perimeter wall 1,333 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 163.50' 12.0" Round Culvert L= 23.0' Ke= 0.500 Inlet/Outlet Invert= 163.50' / 158.32' S= 0.2252 T Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 163.50' 4.0"Vert. Orifice/Grate C= 0.600 #3 Device 1 164.30' 6.0"Vert. Orifice/Grate C= 0.600 #4 Device 1 165.20' 12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #5 Discarded 162.50' 1.020 inlhr Exfiltration over Surface area Phase-In= 0.01' Discarded OutFlow Max=0.01 cfs @ 3.96 hrs HW=162.54' (Free Discharge) 5=Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max=1.41 cfs @ 12.15 hrs HW=165.25' TW=0.00' (Dynamic Tallwater) =Culvert (Passes 1.41 cfs of 4.22 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.53 cfs @ 6.05 fps) 3=Orifice/Grate (Orifice Controls 0.79 cfs @ 4.01 fps) =Orifice/Grate (Weir Controls 0.10 cfs @ 0.69 fps) Summary for Pond 4P: Detention System 1 Inflow Area = 43,305 sf, 92.68% Impervious, Inflow Depth = 4.12" for 25-Year event Inflow = 3.72 cfs @ 12.08 hrs, Volume= 14,885 cf Outflow = 0.81 cfs @ 12.71 hrs, Volume= 14,711 cf, Atten= 78%, Lag= 37.8 min Primary 0.81 cfs @ 12.71 hrs, Volume= 14,711 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs/ 3 Peak Elev= 165.38' @ 12.71 hrs Surf.Area= 5,300 sf Storage= 6,495 cf Plug-Flow detention time= 157.8 min calculated for 14,707 of (99% of inflow) Center-of-Mass det. time= 150.4 min (917.3 - 766.9 ) Volume Invert Avail.Storage Storage Description #1A 163.90, 329 cf 106.00'W x 50.001 x 2.67'H Field A 14,133 cf Overall - 13,312 cf Embedded = 821 cf x 40.0%Voids #2A 163.90' 8,530 cf retain it 2.0' x 78 Inside#1 Inside= 84.0"W x 24.0"H => 13.78 sf x 8.001 = 110.3 cf Outside= 96.0"W x 32.0"H => 21.33 sf x 8.001 = 170.7 cf 13 Rows adjusted for 71.8 cf perimeter wall 8,859 of Total Available Storage 505 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr 25-Year Rainfa11=6.00" Prepared by Microsoft Printed 8/29/2019 HydroCAD®_10.00-13 s/n 00401 0 2014 HydroCAD Software Solutions LLC Page 47 Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 159.00' 12.0" Round Culvert L= 34.0' Ke= 0.500 Inlet/Outlet Invert= 159.00'/ 158.32' S= 0.0200 7 ' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 163.90' 3.0"Vert. Orifice/Grate C= 0.600 #3 Device 1 164.30' 8.0" W x 2.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 165,60' 4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 Primary OutFlow Max=0.81 cfs @ 12.71 hrs HW=165.38' TW=0.00' (Dynamic Tailwater) t--E2=0 ulvert (Passes 0.81 cfs of 9.17 cfs potential flow) rifice/Grate (Orifice Controls 0.28 cfs @ 5.61 fps) =Orifice/Grate (Orifice Controls 0.53 cfs @ 4.81 fps) =Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Pond 5P: Infiltration System 4 Inflow Area = 15,214 sf,100.00% Impervious, Inflow Depth = 5.76" for 25-Year event Inflow - 2.05 cfs @ 12.08 hrs, Volume= 7,305 cf Outflow - 0.66 cfs @ 12.37 hrs, Volume= 7,305 cf, Atten= 68%, Lag= 17A min Discarded = 0.05 cfs @ 8.67 hrs, Volume= 5,088 of Primary - 0.61 cfs @ 12.37 hrs, Volume= 2,217 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 167.39' @ 12.37 hrs Surf.Area= 2,116 sf Storage= 2,826 cf Plug-Flow detention time= 276.6 min calculated for 7,303 cf (100% of inflow) Center-of-Mass det, time= 276.7 min ( 1,021.8 - 745A } Volume Invert Avail.Storage Storage Description #1 165.50' 635 cf Custom Stage Data (Prismatic)Listed below (Recalc) 6,708 cf Overall - 5,120 cf Embedded = 1,588 cf x 40.0% Voids #2 166.00' 3,308 of retain it 2.0' x 30 Inside#1 Inside= 84.0"W x 24.0"H => 13.78 sf x 8.001 = 110.3 cf Outside= 96.0"W x 32.0"H => 21.33 sf x 8.001 = 170.7 cf 3,943 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) TT(sq-ft) (cubic-feet) (cubic-feet) 165.50 2,116 0 0 168.67 2,116 6,708 6,708 606 Sutton Proposed Conditions Hydrologic Analysis Type 11l 24-hr 25-Year Rainfall=6.00" Prepared by Microsoft Printed 8/29/2019 HydroCAD810.00-13 s/n 00401 02014 HydroCAD Software Solutions LLC Page 48 Device Routing Invert Outlet Devices _ #1 Primary 165.40' 12.0" Round Culvert L= 30.0' Ke= 0.500 Inlet/ Outlet Invert= 165.40' / 164.95' S= 0.0150 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 167.00' 12.0"W x 3.0" H Vert. Orifice/Grate C= 0.600 #3 Device 1 167.80' 9.0"Vert. Orifice/Grate C= 0.600 #4 Device 1 168.00' 4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 #5 Discarded 165.50' 1.020 inlhr Exfiltration over Surface area Phase-In= 0.01' Discarded OutFlow Max=0.05 cfs @ 8.67 hrs HW=165.53' (Free Discharge) t--5=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=0.61 cfs @ 12.37 hrs HW=167.39' TW=165.26' (Dynamic Tailwater) t =Culvert (Passes 0.61 cfs of 4.61 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.61 cfs @ 2.44 fps) 3=Orifice/Grate ( Controls 0.00 cfs) =Broad-Crested Rectangular Weir (Controls 0.00 cfs) Summary for Pond 6P: Infiltration Trench Inflow Area = 2,552 sf,100.00% Impervious, Inflow Depth = 5.76" for 25-Year event Inflow = 0.34 cfs @ 12.08 hrs, Volume= 1,225 cf Outflow - 0.34 cfs @ 12.08 hrs, Volume= 1,225 cf, Atten= 0%, Lag= 0.1 min Discarded = 0.01 cfs @ 9.06 hrs, Volume= 410 cf Primary = 0.34 cfs @ 12.08 hrs, Volume= 815 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs/3 Peak Elev= 170.51' @ 12.08 hrs Surf.Area= 232 sf Storage= 71 cf Plug-Flow detention time= 69.1 min calculated for 1,225 cf (100% of inflow) Center-of-Mass det. time= 69.2 min ( 814.3 - 745.1 ) Volume Invert Avail.Storage Storage Description #1 169.00, 70 of Stone Trench (Prismatic)Listed below (Recalc) 174 cf Overall x 40.0% Voids #2 170.50' 12 cf Area Over Trench (Prismatic)Listed below (Recalc) 81 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store feet s -ft cubic-feet cubic-feet 169.00 116 0 0 170.50 116 174 174 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 170.60 116 0 0 170.60 116 12 12 505 Sutton Proposed Conditions Hydrologic Analysis Type 11124-hr 25-Year Rainfall=6.00" Prepared by Microsoft Printed 8/29/2019 H droCADO 10,00-13 sln 00401 0 2014 H droCAD Software Solutions LLC Page 49 Device Routing Invert Outlet Devices #1 Primary 170.50' 70.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #2 Discarded 169.00' 1.020 inlhr Exfiitration over Surface area Phase-In= 0.01' Discarded OutFlow Max=0.01 cfs @ 9.06 hrs HW=170.50' (Free Discharge) t2=Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max=0.34 cfs @ 12.08 hrs HW=170.51' TW=0.00' (Dynamic Tailwater) t--1=Broad-Crested Rectangular Weir (Weir Controls 0.34 cfs @ 0.33 fps) 505 Sutton Proposed Conditions Hydrologic Analysi Type 11124-hr 100-Year Rainfall=8.60" Prepared by Microsoft Printed 812912019 H droCAD® 10.00-13 sln 00401 ©2014 H droCAD Software Solutions LLC Page 50 Summary for Subcatchment PSI: Runoff - 5.39 cfs @ 12.08 hrs, Volume= 18,725 cf, Depth= 8.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24hr 100-Year Rainfall=8.60" Area (sn CN Description 3,170 74 >75% Grass cover, Good, HSG C 23,273 98 Paved parking, HSG C 661 98 Roofs, HSG C 987 98 Unconnected pavement, HSG C 28,091 95 Weighted Average 3,170 11.28% Pervious Area 24,921 88.72% Impervious Area 987, 3.96% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ftlsec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS10: Runoff - 2.68 cfs @ 12.08 hrs, Volume= 9,644 cf, Depth= 8.36" Runoff by SCS TR-20 method, UH-SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24hr 100-Year Rainfall=8.60" Area (so CN Description 13,844 98 Roofs, HSG C 13,844 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ftlsec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PSI 1: Runoff - 2.95 cfs @ 12.08 hrs, Volume= 10,599 cf, Depth= 8.36" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=8.60" Area (so CN Description 15,214 98 Roofs, HSG C 15,214 100.00% Impervious Area 505 Sutton Proposed Conditions Hydrologic Analysi Type f!! 24-hr 900-Year Rainfall=8.60" Prepared by Microsoft Printed 8/29/2019 HHydroCADO 10.00-13 sln 004010 2014 HydroCAD Software Solutions LLC Page 51 Tc Length Slope Velocity Capacity Description (min) feet} eft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PSI 2: Runoff = 1.88 cfs @ 12.09 hrs, Volume= 5,840 cf, Depth= 5.47" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0,00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=8.60" Areas CN Description 12,822 74 >75% Grass cover, Good, HSG C 12,822 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS2: Runoff = 2.63 cfs @ 12.08 hrs, Volume= 9,039 cf, Depth= 7.88" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=8.60" Area (sf) CN Description 2,572 74 >75% Grass cover, Good, HSG C 6,226 98 Paved parking, HSG C 1,474 98 Roofs, HSG C 3,495 98 Unconnected pavement, HSG C 13,767 94 Weighted Average 2,572 18.68% Pervious Area 11,195 81.32% Impervious Area 3,495 31.22% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS3: Runoff - 1.61 cfs @ 12.08 hrs, Volume= 5,413 cf, Depth= 7.52" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36,00 hrs, dt= 0.01 hrs Type ill 24-hr 100-Year Rainfall=8.60" 505 Sutton Proposed Conditions Hydrologic Analysi Type 11l 24-hr 100-Year Rainfall=8.60" Prepared by Microsoft Printed 8/29/2019 HydroCAD® 10.00-13 s/n 00401 02014 HydroCAD Software Solutions LLC Page 52 Area (sf) CN Description 2,355 74 >75% Grass cover, Good, HSG C 5,874 98 Paved parking, HSG C 34 98 Roofs, HSG C 378 98 Unconnected pavement, HSG C 8,641 91 Weighted Average 2,355 27.25% Pervious Area 6,286 72.75% Impervious Area 378 6.01% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS4: Runoff 1.95 cfs @ 12.09 hrs, Volume= 6,149 of, Depth= 6.19" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=8.60" Area (so CN Description _ 8,762 74 >75% Grass cover, Good, HSG C 3,160 98 Paved parking, HSG C 11,922 80 Weighted Average 8,762 73.49% Pervious Area 3,160 26.51% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftift) (ftlsec) (cfs) _ 6.0 Direct Entry, Summary for Subcatchment PS5: Runoff = 2.09 cfs @ 12.08 hrs, Volume= 6,873 cf, Depth= 7.163E Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=8.60" Area (sf) CN Description 4,846 74 >75% Grass cover, Good, HSG C 5,452 98 Paved parking, HSG C 95 98 Roofs, HSG C 1,133 98 Unconnected pavement, HSG C 11,526 88 Weighted Average 4,846 42.04% Pervious Area 6,680 57.96% Impervious Area 1,133 16.96% Unconnected 505 Sutton Proposed Conditions Hydrologic Analysi Type IR 24-hr 100-Year Rainfall=8.60" Prepared by Microsoft Printed 8/29/2019 H droCAD® 10,00-13 s/n 00401 0 2014 H droCAD Software Solutions LLC Page 53 Tc Length Slope Velocity Capacity Description min feet ft/ft ftlsec cfs 6.0 Direct Entry, Summary for Subcatchment PSG: Runoff = 0.78 cfs @ 12.09 hrs, Volume= 2,434 cf, Depth= 5.47" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=8.60" Areas CN Description 5,343 74 >75% Grass cover, Good, HSG C 5,343 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS7: Runoff -- 0.39 cfs @ 12.09 hrs, Volume= 1,214 cf, Depth= 5.47" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=8.60" Areas CN Description 2,666 74 >75% Grass cover, Good, HSG C 2,666 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/fk ftlsec cfs &0 Direct Entry, Summary for Subcatchment PS8: Runoff = 3.04 cfs @ 12.09 hrs, Volume= 9,519 cf, Depth= 5.47" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=8.60" Area (sf), ,. C N Description 20,900 74 >75% Grass cover, Good, HSG C 20,900 100.00% Pervious Area 505 Sutton Proposed Conditions Hydrologic Analysi Type 11124-hr 100-Year Rainfall=8.60" Prepared by Microsoft Printed 8/29/2019 H droCAD® 10.00-13 sln 00401 ©2014 H droCAD Software Solutions LLC Page 54 Tc Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 4.9 50 0.0300 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 1.3 210 0.0290 2.74 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.0 20 0.3500 9.52 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 6.2 280 Total Summary for Subcatchment PS8A: Runoff = 0.49 cfs @ 12.08 hrs, Volume= 1,778 cf, Depth= 8.36" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=8.60" Areas CN Description 587 98 Roofs, HSG C 1,965 98 Unconnected pavement, HSG C 2,552 98 Weighted Average 2,552 100.00% Impervious Area 1,965 77.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ftlsec) (cfs) 6.0 Direct Entry, Summary for Subcatchment PS9: Runoff = 3.48 cfs @ 12.08 hrs, Volume- 12,513 cf, Depth= 8.36" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=8.60" Area (sf) CN Description 17,961 98 Roofs, HSG C 17,961 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ftlsec) (cfs) 6.0 Direct Entry, Summary for Reach DP1: (40] Hint: Not Described (Outflow=Inflow) Inflow Area = 126,309 sf, 78.59% Impervious, Inflow Depth > 6.53" for 100-Year event Inflow - 10.12 cfs @ 12.11 hrs, Volume= 68,729 cf Outflow = 10.12 cfs @ 12.11 hrs, Volume= 68,729 cf, Atten= 0%, Lag= 0.0 min i i 505 Sutton Proposed Conditions Hydrologic Analysi Type 11124-hr 100-Year Rainfall=8.60" Prepared by Microsoft Printed 8/29/2019 H droCAD® 10.00-13 sin 00401 02014 H droCAD Software Solutions LLC Page 55 Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Summary for Reach DP2: [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 23,452 sf, 10.88% Impervious, Inflow Depth = 5.55" for 100-Year event Inflow = 3.53 cfs @ 12.09 hrs, Volume= 10,839 cf Outflow 3.53 cfs @ 12.09 hrs, Volume= 10,839 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Summary for Reach DP3: [40] Hint: Not Described (Outflow=I nf low) Summary for Reach DP4: [40] Hint: Not Described (Outflow=I nf low) Inflow Area = 12,822 sf, 0.00% Impervious, Inflow Depth = 5.47" for 100-Year event Inflow - 1.88 cfs @ 12.09 hrs, Volume= 5,840 cf Outflow = 1.88 cfs @ 12.09 hrs, Volume= 5,840 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Summary for Reach DP5: [40] Hint: Not Described (Outflow-Inflow) Inflow Area = 2,666 sf, 0.00% Impervious, Inflow Depth = 5.47" for 100-Year event Inflow - 0.39 cfs @ 12.09 hrs, Volume= 1,214 cf Outflow = 0.39 cfs @ 12.09 hrs, Volume= 1,214 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Summary for Pond 1 P: Retain It Inflow Area = 31,945 sf, 75.90% Impervious, Inflow Depth = 7.65" for 100-Year event Inflow - 5.88 cfs @ 12.08 hrs, Volume 20,359 cf Outflow = 2.46 cfs @ 12.28 hrs, Volume= 20,359 cf, Atten= 58%, Lag= 11.9 min Discarded = 0.03 cfs @ 4.20 hrs, Volume= 3,149 cf Primary = 2.43 cfs @ 12.28 hrs, Volume= 17,210 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 505 Sutton Proposed Conditions Hydrologic Analysi Type ///24-hr 900-Year Rainfall=8.60" Prepared by Microsoft Printed 8/29/2019 H droCADO 10.00-13 sln 00401 0 2014 H droCAD Software Solutions LLC Page 56 Peak Elev= 166.49' @ 12.28 hrs Surf.Area= 1,460 sf Storage= 4,644 cf Plug-Flow detention time= 41.8 min calculated for 20,354 of(100% of inflow) Center-of-Mass det. time= 41.8 min ( 798.9 - 767.1 ) Volume Invert Avail.Stora e Storage Description #1A 162.00' 867 cf 146.00'W x 10.00%x 6.17'H Field A 7,543 cf Overall - 5,376 cf Embedded = 2,167 cf x 40.0% Voids #2A 162.50' 3,870 cf retain_it 4.0' x 18 Inside#1 Inside= 84.0"W x 48.0"H => 28.87 sf x 8.001 = 230.9 cf Outside= 96.0"W x 56.0"H => 37.33 sf x 8.00'L = 298.7 cf 18 Rows adjusted for 286.9 cf perimeter wall 4,737 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 162.50' 12.0" Round Culvert L= 112.0' Ke= 0.500 Inlet/ Outlet Invert= 162.50' / 153.84' S= 0.07737' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 162.50' 6.0"Vert. Orifice/Grate C= 0.600 #3 Device 1 164.50' 3.0"Vert. Orifice/Grate C= 0.600 #4 Device 1 166.40' 12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #5 Discarded 162.00' 1.020 in/hr Exfiltratlon over Surface area Phase-In= 0.01' Discarded OutFlow Max=0.03 cfs @ 4.20 hrs HW=162.05' (Free Discharge) 'L5=Exfiltrat1on (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=2.43 cfs @ 12.28 hrs HW=166.49' TW=0.00' (Dynamic Tailwater) 'L1=Culvert (Passes 2.43 cfs of 7.06 cfs potential flow) 2=Orifice/Grate (Orifice Controls 1.83 cfs @ 9.31 fps) 3=Orifice/Grate (Orifice Controls 0.32 cfs @ 6.58 fps) =OrificelGrate (Weir Controls 0.28 cfs @ 0.98 fps) Summary for Pond 2P: Retain It Inflow Area = 13,767 sf, 81.32% Impervious, Inflow Depth = 7.88" for 100-Year event Inflow - 2.63 cfs @ 12.08 hrs, Volume= 9,039 cf Outflow - 1.39 cfs @ 12.21 hrs, Volume= 9,039 cf, Atten= 47%, Lag= 7.7 min Discarded = 0.02 cfs @ 5.82 hrs, Volume= 2,091 cf Primary 1.37 cfs @ 12.21 hrs, Volume= 6,948 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs/3 Peak Elev= 165.46' @ 12.21 hrs Surf.Area= 900 sf Storage= 2,287 cf Plug-Flow detention time= 81.6 min calculated for 9,036 cf (100% of inflow) Center-of-Mass det. time= 81.7 min ( 841.4- 759.7 } 505 Sutton Proposed Conditions Hydrologic Analysi Type 11124-hr 100-Year Rainfalh8.60" Prepared by Microsoft Printed 8/29/2019 H droCADO 10.00-13 sin 00401 ©2014 H droCAD Software Solutions LLC Page 57 Volume Invert Avail.Stora e Storage Description 91A 162.00' 400 cf 50.00'W x 18.00'L x 4.67'H Field A 41200 cf Overall - 3,200 cf Embedded = 1,000 of x 40.0% Voids #2A 162,50' 2,311 cf retain it 3.6' x 12 Inside#1 Inside= 84.0"W x 42.0"H => 25.10 sf x 8.001 = 200.8 cf Outside= 96.0"W x 50.0"H => 33.33 sf x 8.00'L = 266.7 cf 6 Rows adjusted for 98.2 cf perimeter wall 2,711 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 162.50' 12.0" Round Culvert L= 23.0' Ke= 0.500 Inlet 1 Outlet Invert= 162.50' 1 158.32' S= 0.1817 T Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 162.90' 4.0"Vert. Orifice/Grate C= 0.600 #3 Device 1 163.80' 3.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 164.80' 4.0"Vert. Orifice/Grate C= 0.600 #5 Device 1 165.40' 12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #6 Discarded 162.00' 1.020 Inlhr Exfiltration over Surface area Phase-In= 0.01' Discarded OutFlow Max=0.02 cfs @ 5.82 hrs HW=162.05' (Free Discharge) t---6=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=1.37 cfs @ 12.21 hrs HW=165.45' TW=0.00' (Dynamic Tailwater) t-- =Culvert (Passes 1.37 cfs of 5.93 cfs potential flow) 2=OrificelGrate (Orifice Controls 0.65 cfs @ 7.44 fps) 3=OrificelGrate (Orifice Controls 0.29 cfs @ 5.96 fps) =0rifice1Grate (Orifice Controls 0.29 cfs @ 3.36 fps) S=OrificelGrate (Weir Controls 0.13 cfs @ 0.77 fps) Summary for Pond 3P: Retain It Inflow Area = 13,844 sf,100.00% Impervious, Inflow Depth = 8.36" for 100-Year event Inflow - 2.68 cfs @ 12.08 hrs, Volume= 9,644 cf Outflow = 2,59 cfs @ 12.11 hrs, Volume= 9,644 cf, Atten= 3%, Lag= 1.3 min Discarded = 0.01 cfs @ 2.38 hrs, Volume= 1,583 cf Primary = 2.58 cfs @ 12.11 hrs, Volume= 8,061 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36,00 hrs, dt= 0.01 hrs / 3 Peak Elev= 165.43' @ 12.11 hrs Surf.Area= 612 sf Storage= 1,273 cf Plug-Flow detention time= 63.6 min calculated for 9,642 cf (100% of inflow) Center-of-Mass det. time= 63.7 min { 804.0 - 740.3 ) 505 Sutton Proposed Conditions Hydrologic Analysi Type 1/124-hr 100-Year Rainfali=8.60" Prepared by Microsoft Printed 8/29/2019 HydroCADO 10.00-13 s/n 00401 ©2014 HydroCAD Software Solutions LLC __Page 58 Volume Invert Avail.Stora e Storage Description #1A 162.50' 249 cf 34.00'W x 18.001 x 3.67'H Field A 2,244 cf Overall - 1,621 cf Embedded = 623 cf x 40.0% Voids #2A 163.00' 1,084 of retain it 2.5' x 8 Inside#1 Inside= 84.0"W x 30.0"H => 17.56 sf x 8.001 = 140.4 cf Outside= 96.0"W x 38.0"H => 25.33 sf x 8.001 = 202.7 cf 4 Rows adjusted for 39.6 cf perimeter wall 1,333 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 163.50' 12.0" Round Culvert L= 23.0' Ke= 0.500 Inlet/Outlet Invert= 163.50' / 158.32' S= 0.2252 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 163.50' 4.0"Vert. Orifice/Grate C= 0.600 #3 Device 1 164.30' 6.0"Vert. Orifice/Grate C= 0.600 #4 Device 1 165.20' 12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #5 Discarded 162,50' 1.020 in/hr Exfiltration over Surface area Phase-In= 0.01' Discarded OutFlow Max=0.01 cfs @ 2.38 hrs HW=162.54' (Free Discharge) 'L5=Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max=2.57 cfs @ 12.11 hrs HW=165.43' TW=0.00' (Dynamic Tailwater) tLE=Culvert (Passes 2.57 cfs of 4.52 cfs potential flow) =Orifice/Grate (Orifice Controls 0.56 cfs @ 6.39 fps) =Orifice/Grate (Orifice Controls 0.89 cfs @ 4.51 fps) =Orifice/Grate (Weir Controls 1.13 cfs @ 1.57 fps) Summary for Pond 4P: Detention System 1 Inflow Area = 43,305 sf, 92.68% Impervious, Inflow Depth = 6.56" for 100-Year event Inflow = 6.22 cfs @ 12.09 hrs, Volume= 23,676 cf Outflow - 2.60 cfs @ 12.42 hrs, Volume= 23,488 cf, Atten= 58%, Lag= 19.8 min Primary = 2.60 cfs @ 12.42 hrs, Volume= 23,488 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs/ 3 Peak Elev= 165.87' @ 12.42 hrs Surf.Area= 5,300 sf Storage= 8,661 cf Plug-Flow detention time= 134.3 min calculated for 23,481 cf (99% of inflow) Center-of-Mass det. time= 129.2 min ( 890.8- 761.5 ) Volume Invert Avail.Storage Storage Description #1A 163.90' 329 of 106.00'W x 50.00'L x 2.67'H Field A 14,133 cf Overall - 13,312 cf Embedded = 821 cf x 40.0% Voids #2A 163.90' 8,530 of retain it 2.0' x 78 Inside#1 Inside= 84.0"W x 24.0"H => 13.78 sf x 8.001 = 110.3 cf Outside= 96.0"W x 32.0"H => 21.33 sf x 8.001 = 170.7 of 13 Rows adjusted for 71.8 cf perimeter wall 8,859 of Total Available Storage 505 Sutton Proposed Conditions Hydrologic Analysi Type IR 24-hr 100-Year Rainfafl=8.60" Prepared by Microsoft Printed 8/29/2019 H droCADO 10.00-13 s/n 00401 ©2014 H droCAD Software Solutions LLC Page 59 Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 159.00' 12.0" Round Culvert L= 34.0' Ke 0,500. Inlet/Outlet Invert= 159.00' 1158.32' S= 0.0200 T Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 163.90' 3.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 164.30' 8.0"W x 2.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 165.60' 4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2,80 2.92 3.08 3.30 3.32 Primary OutFlow Max=2.60 cfs @ 12.42 hrs HW=165.87' TW=0.00' (Dynamic Tailwater) E3=Orifice/Grate ulvert (Passes 2.60 cfs of 9.55 cfs potential flow) t =Orifice/Grate (Orifice Controls 0.32 cfs @ 6.56 fps) (Orifice Controls 0.65 cfs @ 5.88 fps) =Broad-Crested Rectangular Weir (Weir Controls 1.63 cfs @ 1.49 fps) Summary for Pond 5P; Infiltration System 4 Inflow Area = 15,214 sf,100.00% Impervious, Inflow Depth = 8.36" for 100-Year event Inflow = 2.95 cfs @ 12.08 hrs, Volume= 10,599 cf Outflow 1.22 cfs @ 12.28 hrs, Volume= 10,599 cf, Atten= 59%, Lag= 11.9 min Discarded = 0.05 cfs @ 7.22 hrs, Volume= 5,648 cf Primary 1.17 cfs @ 12.28 hrs, Volume= 4,951 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 1 3 Peak Elev= 167.95' @ 12,28 hrs Surf.Area= 2,116 sf Storage= 3,797 cf Plug-Flow detention time= 226.7 min calculated for 10,599 cf(100% of inflow) Center-of-Mass det. time= 226.7 min ( 967.0 - 740.3 } Volume Invert Avail.Stora e Storage Description #1 165.50' 635 of Custom Stage Data (Prismatic)Listed below (Recalc) 6,708 cf Overall - 5,120 cf Embedded = 1,588 cf x 40.0% Voids #2 166.00' 3,308 cf retain it 2.0' x 30 Inside#1 Inside= 84.0"W x 24.0"H => 13.78 sf x 8.001 = 110.3 cf Outside= 96.0"W x 32.0"H => 21.33 sf x 8.001 = 170.7 cf 3,943 of Total Available Storage Elevation Surf.Area Inc.Store Cum.Store feet s -ft cubic-feet cubic-feet 165.50 2,116 0 0 168.67 2,116 6,708 6,708 505 Sutton Proposed Conditions Hydrologic Analysi Type III 24-hr 100-Year Rainfall=8.60" Prepared by Microsoft Printed 8/29/2019 HydroCAD® 10.00-13 s/n 00401 ®2014 HydroCAD Software Solutions LLC Page_60__ Device Routing Invert Outlet Devices #1 Primary 165.40' 12.0" Round Culvert L= 30.0' Ke= 0.500 Inlet/Outlet Invert= 165.40' / 164.95' S= 0.0150 7' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #2 Device 1 167.00' 12.0"W x 3.0" H Vert.OrificelGrate C= 0.600 #3 Device 1 167.80' 9.0"Vert. Orifice/Grate C= 0.600 #4 Device 1 168.00' 4.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 #5 Discarded 165.50' 1.020 inlhr Exfiltration over Surface area Phasedn= 0.01' Qiscarded OutFlow Max=0.05 cfs @ 7.22 hrs HW=165.53' (Free Discharge) T--5=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=1.17 cfs @ 12.28 hrs HW=167.95' TW=165.81' (Dynamic Tailwater) 't-1=Culvert (Passes 1.17 cfs of 5.41 cfs potential flow) 2=Oriflce/Grate (Orifice Controls 1.09 cfs @ 4.36 fps) 3=Orifice/Grate (Orifice Controls 0.08 cfs @ 1.31 fps) =Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Pond 6P: Infiltration Trench Inflow Area = 2,552 sf,100.00% Impervious, Inflow Depth = 8.36" for 100-Year event Inflow - 0.49 cfs @ 12.08 hrs, Volume= 1,778 of Outflow - 0.49 cfs @ 12.08 hrs, Volume= 1,778 cf, Atten= 0%, Lag= 0.0 min Discarded = 0.01 cfs @ 7.32 hrs, Volume= 458 cf Primary = 0.49 cfs @ 12.08 hrs, Volume= 1,320 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs/ 3 Peak Elev= 170.52' @ 12.08 hrs Surf.Area= 232 sf Storage= 72 cf Plug-Flow detention time= 52.2 min calculated for 1,777 cf (100% of inflow) Center-of-Mass det. time= 52.3 min ( 792.6 - 740.3 ) Volume Invert Avail.Stora a Storage Description #1 169.00' 70 cf Stone Trench (Prismatic)Listed below (Recalc) 174 of Overall x 40.0% Voids #2 170.50' 12 cf Area Over Trench (Prismatic)Listed below (Recalc) 81 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 169.00 116 0 0 170.50 116 174 174 Elevation Surf.Area Inc.Store Cum.Store feet s -ft cubic-feet cubic-feet 170.50 116 0 0 170.60 116 12 12 505 Sutton Proposed Conditions Hydrologic Analysi Type 1l124-hr 100-Year Rainfall=8.60" Prepared by Microsoft Printed 8/29/2019 H droCADO 10.00-13 s/n 00401 0 2014 H droCAD Software Solutions LLC Page 61 0 Device Routines _ Invert Outlet Devices #1 Primary 170,50' 70.0' long x 1.0' breadth Broad-Crested Rectangular Weir eir Head (feet) 0,20 0.40 0.60 0.80 1.00 1.20 1,40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3,31 3.30 3.31 3.32 #2 Discarded 169.00' 1.020 inlhr Exfiltration over Surface area Phase-In= 0.01' Discarded OutFlow Max=0.01 cfs @ 7.32 hrs HW=170.50' (Free Discharge) t2=Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max=0.49 cfs @ 12.08 hrs HW=170.52' TW=0.00' (Dynamic Tailwater) t-1=Broad-Crested Rectangular Weir (Weir Controls 0.49 cfs @ 0.37 fps) +I The, M6rin C 6p . . I September 3, 2019 i North Andover Planning Board C/o Eitan Goldberg, Chair Town of North Andover 130 Main Street North Andover, MA 01845 RE: Response to Comments Application for Site Plan Approval 505 Sutton Street/Sutton Street Redevelopment, LLC On behalf of the owner, Sutton Street Redevelopment, LLC (Applicant), The Morin-Cameron Group, Inc.(MCG) has provided the following responses to the TEC Company 2"d peer review comments issued on August 29, 2019. The Peer Review comments are listed below in italics, with MCGs response following. Comments that require no further response from MCG have been omitted for clarity. Included with this submission are the following: Sheet CA from "Multifamily Site Development Plans in North Andover, Massachusetts, 505 Sutton Street" by The Morin-Cameron Group, Inc. dated May 16, 2019 and revised through September 3, 2019. We offer the following in response to the Engineering Corp (TEC) comments: 18. Engineering Comment, Several locations within the site are candidates for stop-signs and stop-bars to control perpendicular traffic at a main drive aisle; or at the major entrant%xit points. Where stop signs are shown on the plan, a stop-bar should be included to accompany the sign. Some key locations on the plans depict both bar and signage. The Applicant shall consider installation of stop sign and stop-barat all those perpendicular locations where minor drive-aisles meet main drive aisles. For instance, the garage exit from Building #2 onto the garage exit from Building#1, MCG Response: The anticipated peak trips from the underground parking garages do not necessitate a stop line and sign. The garages will be used solely by residents of the buildings who will be familiar with the access and circulation.There is excessive driver visibility between the garages. Engineering Comment2.Exiting Building#2, there is an 8-foot retaining wall that will block the drivers view to the left(poor visibility). At a minimum, TEC recommends a stop sign where this driveway intersects the main drive aisle. MCG Response: A stop sign and stop line were added at the exit to Building #2. 21, Engineering Comment. Where additional sidewalk connectivity(from previous comments)is added to the plans, the Applicant shall provide pedestrian crossing signage at the marked crosswalk/uncontrolled location within the site. 7-his signage would be superseded should a stop-sign be warranted at this location. MCG Response: See responses to comments 12 & 13, above, The applicant will defer to the town on these matters. CIVIL ENGINEERS • LAND SURVEYORS ® ENVIRONMENTAL CONSULTANTS e LAND USE PLANNERS 66 Elm Street, Danvers, MA 01923 978.777.8586 FAX 978.774,3488 Providing Professional Services Since 1978 www.morincameron.com i E f North Andover Planning Board 2 September 3, 2019 Engineering Comment 2; 7 E'C recommends the installation of pedestrian crossing signage at the marked crosswalk in the main access driveway to the site. MCG Response: A pedestrian crossing sign was added to the access drive to yield to pedestrians at this location. We trust this information adequately addresses your comments regarding the 505 Sutton Street Site Plan Review application plans. If you have any questions, please do not hesitate to contact our office at (978) 777-8586, Very Truly Y urs, THE 0 MERON GROVP_,-,INC. _- Scott , C meron, PE Prin tpal SPC/abr/kmm Attachments cc: TEC Corporation Sutton Street Development, LLC North Andover Planning Board X:1Minco\3454\oocs\Peer Review Comments\3454 Engineering Response Letter Traffic Review 2 i i I I The Morin-Cameron 1 August 29, 2019 North Andover Planning Board C/o Eitan Goldberg, Chair Town of North Andover 120 Main Street North Andover, MA 01845 RE: Response to Comments Application for Site Plan Approval 505 Sutton Street/Sutton Street Redevelopment, LLC Dear Members of the Board: On behalf of the owner, Sutton Street Redevelopment, LLC (Applicant), The Morin-Cameron Group, Inc. (MCG) has provided the following responses to the Town of North Andover 2"a Stormwater Peer Review report dated August 19, 2019.The Peer Review comments are listed below in italics,with MCG's response following. Comments that require no further response from MCG have been omitted for clarity. Included with this submission are the following: - Sheet C,5 from "Multifamily Site Development Plans in North Andover, Massachusetts, 505 Sutton Street" by The Morin-Cameron Group, Inc, dated May 16, 2019 and revised through August 29, 2019. - Revised Proposed Conditions Hydrologic Analysis HydroCAD. - Retain-it Module Storage Volumes &Weight by Height We offer the following in response to the Horsley Witten Group Stormwater Review comments: 1.a Engineering Comment: The Applicant has analyzed the existing and proposed stormwater discharge rates from the project site at the property boundaries, At the south property boundary, the development discharges stormwater overland towards an isolated vegetated wetland. The flow is not significant towards this resource area and erosion is not anticipated. MCG Response. The site does not drain towards the offsite wetland in either the existing or proposed condition.There is an existing berm along the edge of the property that directs the water towards the east property line, away from the edge of the isolated vegetated wetland. Engineering Comment 2, The Applicant has responded that the Site does not drain towards the offske wetland in either the existing orproposed condition. There is an existing berm along the edge of the property that directs the water towards the east property line, away from the edge of the isolated vegetated wetland. HW recommends that the Applicant note the berm on the site plans with a statement that the berm will remain as existing. MCG Response 2:A note has been added to sheet C,5 for the berm to remain, CIVIL ENGINEERS LAND SURVEYORS ® ENVIRONMENTAL CONSULTANTS o LAND USE PLANNERS 66 Elm Street, Danvers, MA 01923 978.777,8586 FAX 978,774.8488 Providing Professional Services Since 1978 www.morfncameron.com North Andover Planning Board 2 August 29, 2019 2.a Engineering Comment. The Applicant has provided clear documentation to illustrate that the post development peak discharge rates do not exceed pre-development rates. However, the bottom of the stone for each subsurface system listed on Sheet C.12 does not all correlate with the bottom of the stone elevations provided in the HydroCAD modeling calculations HW recommends that the Applicant revisit the plan and calculations for Infiltration Systems#2,43, and#4, as well as Detention System#1. MCG Response:The system locations and elevations were revised to demonstrate compliance with the 2 feet of separation to groundwater. Engineering Comment 2. The Applicant has revised the locations and elevations of the subsurface stormwater practices to demonstrate compliance with the 2 feet separation to groundwater. For clarity HW recommends that the Applicant property label 4P in the HydroCAD model as Detention System#1 and 5P as Infiltration System#4. MCG Response 2:The HydroCAD model has been revised to show 4P as Detention Systern#1 and 5P as Infiltration System #4. 2.b Engineering Comment. For clarity HW recommends that the Applicant list the Retain-It chamber size on Sheet C.12 for each of the individual systems and verify that the correlating details are provided on Sheet C.13. MCG Response:The Retain-it chamber sizes are listed in the leader detailing the total number of units.These sizes have been verified with the correlating detail on sheet C.13. Engineering Comment 2. The Applicant has listed the Retain It dimensions and total number of units for the five subsurface systems on Sheet C 12, The heights listed include 2.67'. 3.17; 4.17'. and 4.67' The Details provided on Sheet C.13 indicate the heights to be 3'8"and 4'8" It appears that the Retain It Chambers comes in variable heights, HW recommends that the Applicant confirm that the heights proposed for the various systems are available as noted. MCG Response 2: The sizes for the systems are available as noted.The module height sheet from the manufacturer is included herein. 2.d Engineering Comment. The Applicant has regraded the entire site including along the western,southern,and eastern property boundaries Under existing conditions, the stormwater flows within the site boundaries towards#19 Surly Drive (west boundary)and#946 Osgood Street (east boundary). Under proposed conditions the site sheet flows towards additional abutting properties, including#25, #35, #43, #51, and#59 Surrey Drive. HW recommends that the Applicant clarify whether the abutting property owners will receive more stormwater under proposed conditions than they do under existing conditions MCG Response: The intent of the grading along the property boundaries is to direct all water back towards design point 3 or the catch basins in the parking area.Sheet CA has been revised to add flow arrows. #51 and #59 Surrey Drive receive no stormwater during existing or proposed conditions due to the existing berm described in response 1.a. Due to the reduced tributary area,#25,#35, &#43 Surrey Drive will receive less runoff,The grades along this area of the site promote sheet flow from vegetated areas only. Engineering Comment 2; The Applicant has stated that the intent of the grading along the property boundaries is to direct all water back towards design point 3 or the catch basins in the parking area. The Applicant stated further, that Sheet C.4 has been revised to add flow arrows However, HW was not able to locate the flow arrows HW recommends that the North Andover Planning Board 3 August 29, 2019 Applicant add a note for the contractor to grade the areas adjacent to the property boundaries to direct runoff into the parking lot. The Applicant also notes, that#51 and#59 Surrey Drive receive no stormwater during existing or proposed conditions due to the existing berm described in response 7.a, Due to the reduced tributary area, #25, #35, &#43 Surrey Drive will receive less runoff. The grades along this area of the site promote sheet flow from vegetated areas only. HW is satisfied that the Applicant will not be directing more stormwater onto the adjacent properties than under existing conditions. MCG Response 2: A note was added to C.5 to grade areas adjacent to property boundaries to direct runoff into the parking lot. We trust this information adequately addresses your comments regarding the 505 Sutton Street Site Plan Review application plans. If you have any questions, please do not hesitate to contact our office at (978) 777-8586. Vekpal THours RO C:"-- C Pri SPC/kmm Attachments cc: Horsley Witten Group, LLC Sutton Street Development, LLC 11 X:1Minco134541Docs\Peer Review Comment513454 Engineering Response Letter stormwater 2