Loading...
HomeMy WebLinkAboutConsultant Review - 58 COUNTRY CLUB CIRCLE 2/13/2017 L[Edrolo ic Report Summary Proposed Site Improvements located at 58 Country Club Circle North Andover, Massachusetts 01845 Prepared For Donald D. Stanley 58 Country Club Circle .North Andover, MA 2, 10, & 100 Year Storm 24 Hour Duration ,�P4t,y Q F /yA SSS GEORGE c� Ll J, ZAM3DURAS CIVIL #3' 30 NAL- - Date: February 13,2017 Atlantic Engineering& Survey Consultants Inc. 97 Tenney Street, Georgetown,Massachusetts 01833 (978) 352-7870 TABLE OF CONTENTS 3 I. INTRODUCTION II. EXISTING CONDITIONS III. PROPOSED CONDITIONS IV. SITE SOILS V. STORMWATER MANAGEMENT VI. SUMMARY VII. ASSUMPTIONS AND DESIGN CRITERIA VIII. PRE-DEVELOPMENT CALCULATIONS—(Not included in summary) IX. POST-DEVELOPMENT CALCULATIONS - (Not included in summary) X. NRCS SOIL REPORT E [ 2 f INTRODUCTION: This report describes the pre and post hydraulic analysis and stormwater management measures proposed to be implemented to mitigate the potential impacts to the Watershed Protection District resulting from the proposed site improvements to the residential property located at 58 Country Club Circle,North Andover, Massachusetts 01845. The design of the stormwater system's components and the computation of pre and post development runoff rates and volumes are based on a hydraulic analysis performed utilizing "HydroCAD Storm water Modeling Software" for storm events of 2, 10 and 100-year storm frequencies. EXISTING CONDITIONS: The project site is located on the northeasterly end of the Country Club Circle cul-de-sac and is bounded by residential properties to the north, south and east; and westerly by the North Andover Country Club. The site is comprised of a 2 acre and developed residential lot. The parcel is within the Watershed Protection District and is located in excess of 400 feet from the mean annual high water mark of Lake Cochichewick, the Town's public drinking water supply. A bordering vegetated wetland(BVW)which is tributary to Lake Cochichewick is located to the east of the site. As a result of the sites proximity to the BVW the site is located within the Non-Discharge Zone and Non-Disturbance Zone of the Watershed Protection District. PROPOSED IMPROVEMENTS: The improvements proposed for the site consist of the following items: • Replacement of existing walkways • Replacement and enlargement of existing patio • Installation of a pool with spa and associated deck • Installation of protective fencing • Installation of a retaining wall • Expansion of lawn area, landscaping and associated fill and grading • Rain Gardens The retaining wall; portions of the pool and pool deck; and portions of the fill, lawn and landscape areas are located within the Non-Disturbance Zone. All other proposed improvements are located within the Non-Discharge Zone. The installation of the rain gardens are proposed to mitigate the increases of post ran-off rates and volumes to levels equal to or below pre-development rates and volumes. ! 3 SITE SOILS: No soil tests were performed and the hydraulic analysis provided herein is based on site soils as classification by NRCS. The NRCS soils report, which is appended to this hydraulic analysis, classifies site soils as those being of the Chatfield-Hollis-Rock outcrop complex. i Chatfield-Hollis-Rock complex soils are comprised of fine to gravelly sandy loams with underlying unweathered bedrock. The Chatfield soils are soils belonging to the hydrologic soil group A and Hollis soils are of the D hydrologic soil group. To take a conservative approach in establishing a comparison of pre and post run-off rates and volumes the site was modeled as HSG B soils in the hydraulic analysis. Additionally the corresponding Rawls infiltration rate of 1.02 inches per hour for HSB B sandy loams is utilized in modeling the infiltration rates for the proposed rain gardens. SILTA TIONAND EORSION CONTROL: To effectively manage the impacts to the environment, to the surrounding properties and to the Watershed Protection District during construction of the of the proposed site improvements the following BMP's are proposed. ➢ Siltation barrier -A siltation barrier will be installed and maintained at the proposed limit of work during construction to control and prevent erosion and transportation of sediments to the resource area and Watershed District. This barrier shall be maintained until suitable growth of vegetation has been established in all disturbed areas. ➢ A Construction entrance will be installed and maintained to prevent erosion and transportation of sediments during construction. ➢ A protected concrete washout area shall be established for collection and for the proper disposal of spent concrete products. ➢ During construction materials will be properly stored and disposed of. ➢ Other construction BMP's shall be utilized as deemed necessary during contraction to ensure the protection of the resource area and Watershed District. 4 SUMMARY. As indicated in the summary below, with the incorporation of the proposed rain gardens, the post-development run-off rates and volumes equal or result a reduction of the pre-development run-off rates and volumes for the 2, 10 and 100-year storm events. Hydraulic Analysis Summary 58 Country Club Circle -- North Andover, MA Summary of Total Site Discharge Flows and Volumes Max. Max. Design Discharge Discharge Max. Volume Max. Volume Storm (CFS.} (CFS.} (CU-FT.) (CU-FT.) Pre- Post- Pre-- Post- Development. Development Development. Development 2 Yr. 0.27 0.30 1,090 1,097 10 Yr. 0.77 0.74 2,565 2,494 .100 Yr. 1.62 .1.62 5,174 5,130 Assumptions: The fallowing assumptions are used for design purposes: 1) 2, 10 & 100 year storm frequency. 2) 24 hour storm duration (min.) 3) The NRCS Hydrologic soils groups for the run-off areas are classified class as "A" —and "D"soils,for the purpose this analysis the soils have been modeled as "B" soils. 4) Existing and proposed Ch values are as noted in the report. 5) Within small drainage areas a minimum Tc value of 6 min. is used. 6) Exfltration rate based on the applicable Rawls rate for loams 1.02 in1hr. [ 5 Design Criteria: 1) Run-off quantities are calculated using TR-20 intensity numbers 2) I=3.1 for 2 yr/24 hr. duration, 4.5 in./25 yr. & 6.5 in./100 yr. 3) Proposed Ch values are as noted in the report. 4) Hyetograph shape T S.C.S.III(eastern U.S.) 5) The maximum flow rate of run-offfor the 2, 10& .100 yr. design storms which are routed through drainage system will be equal or less than pre-development run-off. 6 USDA United States A product of the National Custom Soil Resource Department of Cooperative Soil Survey, Agriculture a joint effort of the United Report for States Department of NRCS Agriculture and other Essex County, Federal agencies, State Natural agencies including the Massachusetts Resources Agricultural experiment , Conservation Stations, and local Service participants Northern Part 58 Country Club Circle r, r js _ s �i�l•IIIII♦Il•�����o�o at w February 1, 2017 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including fanners, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses.The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nres.usda,gov/wpsl portallnreslmain/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https:/loffices.sc.egov.usda,gov/locatorlapp?agency=nres) or your NRCS State Soil Scientist(http:/Iwww.nres.usda.gov/wps/portal/nres/detaillsoils/contactus/? cid=nres142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies.The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status,familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require i 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at(202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800)795-3272 (voice)or(202)720-6382 (TDD). USDA is an equal opportunity provider and employer. E 3 I . . Contents�� ������ ����� ��w Preface...................... ..............................................................................................2 SoilMap.................................................................................................................. 5 SoilMap................................................................................................................6 Legend 7 ----.--.----------------------^-------- MapUnit Legend..................................................................................................* MapUnit Descriptions.......................................................................................... 8 Essex County, K4assoohuuottn, Northern Pert.---------------.. 10 711D--Ohadton'Rookoutcrop-Hollis complex, 15to25percent skopou—..1O � � � � � � � � � � � � � 4 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. i E E I i 5 Custom Soil Resource Report Soil Map Ell M fn n 326930 32ZO 325%) 328560 328570 329580 329593 32M 328610 328M 329630 328640 32W 328960 32867032868D 328690 42°41'26'N 42°41'26'N Q Q v Q a � + Q a - ' i^ it F' L l tm F ..,.4... a Soif rE,�y W2 b� valid t I s' lei ,' r ill!Hilp;i 11 42°41'22'N 42°41'2r N .. •. ,..•f 32865D 32OW 3 8270 328680 32xNM 32$x80 328."#I 3�G0 329560 328570 328580529%0 32060(73296'10 328620 328530 328640 3 7 3 v, n " L, Map Scale:1:775 iFprinted on A landscape(11"x S.5")sheet. Meters 60h ^ N 0 10 20 40 0 © 35 7[} 140 219 Map projection:Web Me€rator Comer Coordinates:WG584 Edge tics:u1M Zone 19N W&584 6 Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of Interest(Adt) Spoil Area The soil surveys that comprise your AOl were mapped at Area of Interest(AOI) 1:15,800. Stony Spot Soils ° Very Ston Sot ry y p Warning:Soil Map may not be valid at this scale. Soil Map Unit Polygons J Kr�f, Wet Spot ' ,A;,s Soil Map Unit Lines Enlargement of maps beyond the scale of mapping can cause Ell Other misunderstanding of the detail of mapping and accuracy of soil Sail Map Unit Points line placement.The maps do not show the small areas of ..� Special Line Features p p Special Point Features contrasting soils that could have been shown at a more detailed Blowout Water Features scale. Streams and Canals Borrow Pit Transportation Please rely on the bar scale on each map sheet for map Clay Spot e F i Rails measurements. Closed depression . Interstate Highways Source of Map: Natural Resources Conservation Service Gravel Pit US Routes Web Soil Survey URL: Gravelly SpotMajor Roads Coordinate System: Web Mercator(EPSG:3857) Landfi[[ Local Roads Maps from the Web Soil Survey are based on the Web Mercator Cava Flow projection,which preserves direction and shape but distorts #., Baokground distance and area.A projection that preserves area,such as the Marsh or swamp Aerial Photography Albers equal-area conic projection,should be used if more accurate calculations of distance or area are required. Mine or Quarry Miscellaneous Water This product is generated from the USDA-NRCS certified data as f Perennial Water of the version date(s)listed below. Rock Outcrop So'l Survey Area: Essex County,Massachusetts,Northern Part Saline Spat Survey Area Data: Version 12,Sep 14,2018 Sandy Spot Soil map units are labeled(as space allows)for map scales a Severely Eroded Spot 1:50,000 or larger. Yr Sinkhole Date(s)aerial images were photographed: Aug 29,2014—Sep Slide or Slip 19,2014 Sodic Spot The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps.As a result,some minor shifting of map unit boundaries may be evident. 7 Custom Soil Resource Report Map Unit Legend Essex County,Massachusetts,Northern Part(MA605) Map Unit Symbol ": Map Unit Name Acres in A01 Percent of 711 D Charlton-Rock outcrop-Hollis 1.5 100.0% complex, 15 to 25 percent slopes Totals for Area of Interest 1.5 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, 8 Custom Soil Resource Report onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a sail series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. 9 Custom Soil Resource Report Essex County, Massachusetts, Northern Part 711 D--Charlton-Rock outcrop-Hollis complex, 15 to 25 percent slopes Map Unit Setting National map unit symbol: vj77 Mean annual precipitation: 45 to 54 inches Mean annual air temperature: 43 to 54 degrees F Frost-free period: 125 to 240 days Farmland classification: Not prime farmland Map Unit Composition Charlton and similar soils: 60 percent Rock outcrop: 16 percent Hollis and similar soils: 15 percent Minor components: 9 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Charlton Setting Landform: Ridges, hills Landform position (two-dimensional): Backslope Landform position (three-dimensional): Side slope Down-slope shape: Linear Across-slope shape: Convex Parent material: Friable coarse-loamy eolian deposits over friable coarse-loamy basal till derived from granite and gneiss Typical profile H1 - 0 to 4 inches: fine sandy loam H2-4 to 28 inches: gravelly fine sandy loam H3-28 to 60 inches: gravelly fine sandy loam Properties and qualities Slope: 15 to 25 percent Percent of area covered with surface fragments: 1.6 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Capacity of the most limiting layer to transmit water(Ksat): Moderately high to high (0.60 to 6.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Moderate (about 7.5 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 6s Hydrologic Soil Group: A Hydric soil rating: No Description of Rock Outcrop Setting Parent material: Granite and gneiss 10 Custom Soil Resource Report Properties and qualities Slope: 15 to 25 percent Depth to restrictive feature: 0 inches to lithic bedrock Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 8s Hydric soil rating: Unranked Description of Mollis Setting Landform: Ridges, hills Landform position (two-dimensional): Backslope Landform position (three-dimensional): Side slope Down-slope shape: Linear Across-slope shape: Convex Parent material: Shallow, friable loamy basal till derived from granite and gneiss over granite and gneiss Typical profile O- 0 to 9 inches: muck H2- 9 to 6 inches: fine sandy loam H3-2 to 97 inches: gravelly fine sandy loam H4- 97 to 20 inches: unweathered bedrock Properties and qualities Slope: 15 to 25 percent Depth to restrictive feature: 10 to 60 inches to lithic bedrock Natural drainage class: Somewhat excessively drained Capacity of the most limiting layer to transmit water(Ksat): Very low (0.00 to 0.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Very low (about 2.5 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 6e Hydrologic Soil Group: D Hydric soil rating: No Minor Components I Woodbridge I Percent of map unit: 7 percent I Hydric soil rating: No Ridgebury Percent of map unit: 2 percent Landform: Depressions Hydric soil rating: Yes 11 i