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74-01 - Minnewashta Woods PUD pt 3SITE PLAN REVIEW of MINNEWASHTA WOODS Preliminary Plat RALPH HEGMAN, OWNER Route 5, Box # 243W Excelsior, Minnesota 55331 Developer: Ecklund & Swedland Construction Co. 19400 Highway #7 Excelsior, Minnesota 55331 Surveyors: Egan Field & Nowak, Inc. 7415 Wayzata Blvd. Minneapolis, Minnesota 55426 Site Plan Review Requested by: Gerald W. Schlenk for Chanhassen Planning Commission Reviewed by: Donald C. Berg, District Conservationist Robert Lueth, Soil Scientist USDA Soil Conservation Service City Hall Waconia, Minnesota 55387 February 5, 1974 In Cooperation With: Carver Soil and Water Conservation District The preliminary plat of Minnewashta Woods has been examined by Donald C. Berl and Robert A. Lueth of the Soil Conservation Service, as requested by the Village of Chanhassen, on January 25, 1974. The 10.92 acre site is located just off the North shore of Lake Minnewashta the NWk, NEk, Section 4, R23W, T116N in the Village of Chanhassen. The drainage is into Lake Minnewashta. The landscape, including the soils,slopes, and existing vegetation was inver toried and evaluated as follows: 1. Suitability of soils for the intended use. 2. Prevention of soil erosion due to land disturbance. 3. Conservation treatment of storm drainage water to control increasec runoff and sediment and protect downstream landowners. 4. Harmonious development of roads and buildings in relation to slope, soils, drainage, and existing trees and shrubs. 5. Construction and maintenance of water and erosion control structure where needed. Soil survey mapping ,units have been drawn over the preliminary plat map and color coded to show building site limitations: Green has slight limitations yNn Yellow has moderate limitations Red has severe limitations -Blue has very severe limitations. The colors show land slopes, land alteration, soil erosion and sediment haza limitations. The colored lines show wetness limitations. The soil mapping units and major building site limitations found on the prop are listed below: Soil Slope Building Site Symbol Soil Name Range Limitations Map C HaB Hayden loam 2 to 6 % Slight land alteration Gre and soil erosion HaC Hayden loam 6 to 12% Moderate land alteration Yell and soil erosion HaD Hayden loam 12 to 18% Severe land alteration I=e and soil erosion Cw Cordova -Webster 0 to 2% Severe wetness Red 1 silty clay loam 'e Glencoe silty 0 to 2% Severe wetness Red 1 clay loam Pm Peat and muck 0 to 2% Organic materials Red 1 1 to 3� feet Very severe wetness over loam #j — 1, to Y...�`4, J Soil Slope Building Site Symbol Soil Name Range Limitations HaE Hayden Loam 18 to 25% Very severe land alteration and soil 'erosion HaF Hayden loam 25 to 40% Very severe land alteration and soil erosion SOIL AND WATER CONSERVATION CONSIDERATIONS Map ( B li B It The Carver Soil and Water Conservation District believes that slopes steeper than 18 percent should be protected and a permanent vegetative cover maintai The vegetative cover should be improved where needed with grass, shrubs, anc plantings. Lots 17, 18, 19, and 20 in Block 2 are on slopes over 18 percent ranging up -to 30 percent. This area is colored blue on the plan map. Land slopes ranging from 12 to 18 percent require that homes and small buil be carefully designed to fit in this steep landscape. Extra care is needed construction to keep landscape alteration to a minimum. Soil conservation p tiles may be needed to control soil erosion and prevent sediment deposition stream in lower lying areas. Lots 2, 5, 6, 119 12, 13, and 15 are on slopes ranging from 12 to 18 percent colored red on the plan map. These lots should have the individual house de signed to fit each lot. Careful excavation and placement of topsoil and spo is required to minimize landscape alteration, control soil erosion, and mini sediment deposition. The disturbed area should be reseeded immediately afte the construction grading is completed. The seeding can be a temporary grass seeding or applied mulch. This is done to protect the land until the final scape plan is prepared and the final grades established. Then the final sod seeding, and tree planting can be completed immediately to protect the poten highly erodible steep slopes. The drainage pattern of this site is such that soil wetness will be a develo problem. The wetness problem is shown by red lines drawn on the plan map. 1, 21 4 and part of 3 in Block 1 is underlain by wet soils. These soils hav high seasonal water table. Apparently the above lots have been partially fi with borrowed soil. Borings through the fill should be taken in the spring determine the location of the high seasonal water table. A plan for proper face drainage, subsurface drainage, basement footing drains, and extra carefi applied basement waterproofing is needed, or basement seepage will be a coat ing problem. Lots 1, 7, 10 and 16 are partially covered by soils having a w netisw problem and seasonal high water table. The same care to insure proper age and construction practices to eliminate basement seepage is needed as de above. The 2 to 6 percent slopes colored green on the map and the 6 to 12 percent s colored yellow on the map are considered to have a slight to moderate erosiol sediment hazard when used for residential development with municipal sewers. The following is a short description of the soils found on the property and limitations for building sites, foundations for low buildings, and streets ( cost roads. HaB, HaC, HaD, HaE, HaF Hayden loam, clay loam Hayden soils consist of undulating to steep, well drained soils formed in g: till on convex upland slopes. The surface layer is very dark gray loam abot inches thick. The subsurface layer is dark grayish brown loam about 7 inch( thick. The subsoil is dominantly yellowish brown firm clay loam about 34 it thick. The underlying material is light olive brown loam. The major building site limitation is very severe landscape alteration and and sediment hazard on the E and F slopes (18 to 40%), severe landscape alt( and erosion and sediment hazard on the D slopes (12 to 18%), and moderate 1, scape alteration and erosion and sediment hazard on the C slopes (6 to 12%). many Hayden areas, water moves through the soil very slowly and basement se( is a common problem. When used as foundations for low buildings, they have a moderate limitation: medium shear strength, moderate shrink -swell potential, medium compressibili medium bearing values, and basement seepage is a common problem. When used for streets and low-cost roads, they have a moderate shrink -swell tential, moderate susceptibility to frost action, moderately fine textured soil, and are found on gently sloping to steep topography. on slopes over 9 the limitation becomes severe because of deep cuts and fills. The road mair ance problems also increase as the slope increases, especially from erosion seepage. Cw Cordova -Webster silty clay loam Ge Glencoe silty clay loam Very poorly drained ciay loam and silty clay loam soils. These medium textu materials are commonly many feet thick. The subsoils are typically neutral. They occupy 1 to 5 acre depressions and 5 to 40 acre long, winding, low grad drainagemays. Commonly associated soils are the poorly drained Wehster soil the sloping Lester and Hayden soils, and the peat and muck soils. The major building site limitation is wetness. The Cordova soil is poorly d and the Glencoe soil is very poorly drained and has a high seasonal water to that ranges from near the surface to a depth of 3 to 5 feet. When used as foundations for low buildings, they have a severe limitation: t water table, medium to low shear strength and bearing values, moderate shrin swell potential, and a medium compressibility. When used for streets and low-cost roads, they have a high seasonal water to are occasionally ponded, and have a high susceptibility to frost action, mod shrink -swell potential, and a moderately fine texture. Pm Peat and muck, moderately shallow over loam Very poorly drained, moderately shallow organic materials (1 to 3k feet dee over loam. They are neutral, very poorly drained, moderately permeable, hi in organic matter with a high water holding capacity. They occur in slough pot holes and drainageways. The major building site limitations are frequent ponding and organic materi that is very poorly drained with the water table near the surface. When used as foundations for low buildings, they have unfavorable soil char teristics, including organic soil that is very poorly drained and has a hig water table. When used for streets and low-cost roads, they have a low bearing capacity the water table near the surface and an organic surface texture. For additional soil information, see "Soil Survey - Carver County, Minnesot. United States Department of Agriculture, Soil Conservation Service, November 1968. The soil investigations, mapping and interpretations ordinarily apply to the upper 5 to 6 feet of soil material. There should be additional onsite inve: gation relating directly to the proposed uses before construction is startec Attached; Development Plan With Soil Mapping Units Colored to Show Building Site Limitations and Color Key