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73-01 - Hesse Farm SUB pt 3UNITED STATES DEPARTMENT OF AGRICULTURE -7ri SOIL CONSERVATION SERVICE City Hall, Waconia, Minnesota 55387 Mr. Lloyd Schnelle, Zoning Administrator Chanhassen City Hall Chanhassen, Minnesota 55317 Dear Lloyd: October 1t 1974-' F� IL! I-Y Here is another summary of the "Hesse Farm Plan", see al=rache4-1,awgs.-mapS, Home site location on slopes less than 127. with 100 feet between wells ani septic tank drainfields is still a problem on some of the lots in this de. velopment plan. I believe it is also prudent to have an alternate drain - field location on each lot that is 100 feet away from the nearest well. This alternate drainfield area then can be used if the original ceases to function properly. The design of the drainfields would be based on an ac- ceptable percolation test. On questionnable lots the planning commission should have the home site, well, septic tank drainfield, and alternate drainfield located on the plat or staked in the field to eliminate to the greatest degree possible futur( and/or continuing problems. Using the above criteria, the following lots are questionnables The yellow color on the map indicates a probable site if the size and the percolation test meet the village requirements. Red lines indicate wet soils on some problem lots. Red solid color indicates steep slopes. Sheet 1 Lot 2, 5, 6, 8 and 9 Lot 2 is both wet and steep. Lots 5, 6, and 9 have an area that may be too small for the home site, wel and drainfield, and alternate drainfields, if these are to be located beta the building set back line and the steeper slopes. Lot 8 has no access road shown, it is disected by a gully and steep slopes The road should be shown along with the home site. 0 M Sheet 2 - Lots 3, 4, 5 and 6 are minimal size and the home site, well septic tank drainfield, with the alternate drainfield, should be located the plan so as not to pollute each ethers wells. Sheet 3 - Lots 7, 8, 11, 12, 13 and 17 and 4 Lots 8, 11, 12 and 13 are minimal size. Lot 7 is cut up by wet soils, steep slopes and a gully. Home siting cou: be poorly done on this lot. Lot 17 may have a minimal home site on top of a ridge surrounded by steel slopes. Drainfield effluent seepage could be a problem here if not care- fully considered. Lot 4 is a to W wet soil area and backs up water from the pond. Sheet 4 - Road Plan and Profiles The roads have 4awL steep grades 57. and greater, with no sod indicated fc erosion control in these steeper road ditches. The roads also cross low areas with questionnable soils. The project engineer should show the roc ditches that require sod to control erosion, as well as methods used to 9 sure a good road bed in the low wet soil areas. Where the road cuts acro: a steep slope, a cross section and bank stabilization..methods that may bE needed should be shown. Existing Gully Heads Regarding the 5 gully heads referred to in an earlier report, the project engineer should provide the method of grade stabilization that will be u! to control these gullies. Sincerely, !`z��r,ald C. Berg District Conser tionist HESSE FARM FIRST ADDITION REVIEW 7-17-74 The First Addition is divided into 10 lots in two blocks; 4 lots are local on the North side of the road and 6 lots on the South side of the road. The steeper Hayden soils are colored red (12 to 18%) and blue (18 to 40%). red lined areas on the map outlines the Terril (TeB), Cordova (Cs), and G] (Ge) soil areas. These soils have a high seasonal water table. ThereforE home site location should be made very carefully to avoid excessive landsc alteration, soil erosion, and sediment damage, septic tank and drainfield failures, and wet basements. Rome site location and septic tank drainfield location are the two primary problems on this plan. The home site should preferrably be located on sle of less than 12%9 shown with solid green and yellow colors on the attached "First Addition" map. Home sites should not be located on the red lined a (shown on the map) because of the high seasonal water tables septic drainf will not function, and basement seepage will be a continuing problem. The areas colored solid blue on the map are slopes over 18% and should be avoi too. It is very difficult to construct a septic tank and level drainfield slopes over 12% and hillside seepage of effluent is a common problem and c tinning erosion can be a problem also. The areas having 12 to 18% slopes (colored red on the map) are more diffic to locate a home, well and septic tank on, and require very careful siting avoid drainfield effluent seepage and continuing erosion problems. The home site area on each lot should be large enough to accommodate the h well, septic tank and drainfield, allowing the proper spacings to avoid we water contamination. Some of the home sites may be located well off the main road shown on the The indrives should be constructed to minimize erosion, and some thought s be given to winter snow removal. There are two gully heads in this "First Addition". These should be inves gated for stability and care should be taken not to divert additional runo water into them. Sees Metro Association of Soil and Water Conservation D trict "Urban Erosion Control Handbook" Standards and Specifications for Gr, Stabilization Structures, pp 45-48. Lot 3 in the "First Addition" on the North side of the road will be the mo difficult lot to locate a home site on because of both Wetness and steep s The following is a comment on the uncolored area "Phase Two" portion of the attached map. Lots 3, 49 S, 6 and 7 may not have a large enough lot area between the steep slope and the road set back line to accommodate a home, well, septic tank and drainfield. Perhaps staking the road out in this area for the Planning Commission and the owner's review would resolve the problem. For additional information on this land, see reports and maps of July 12, and June 4, 1974. For additional soil information, see "Soil Survey - Carver County, Minnesot United States Department of Agriculture, Soil Conservation Service, Aovembe 1968. SITE PLAN REVIEW of HESSE FARM in CHANHASSEN, MINNESOTA Preliminary Sketch Plan by Herb Baldwin Landscape Architect Jordan, Minnesota 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 July 12, 1973 In Cooperation With: Carver Soil and Water Conservation District I have reviewed the 336.75 acre "Hesse Farm'* preliminary sketch plan as sub to the Carver Soil and Water Conservation District on July 2, 1973. This s planned into three areas with a total of 47 lots, 1 park (10.67 acres) and lot (23.33 acres) South of the railroad tracks. The attached development plan has been color coded to show soil mapping uni building site limitationss Green has slight limitations Yellow has moderate limitations Red has severe limitations Blue has very severe limitations. Solid colors show land slopes, land alteration, soil erosion and sediment h limitations. Lined colors show water, wetness, and seepage limitations. The soil mapping units and major building site limitations found on the pro] are listed below: Soil Slope Building Site Symbol Soil dame Range Limitations Map Co HaB Hayden loam 2 to 6% Slight land alteration Greei and soil erosion EsC Estherville sandy loam 6 to 12% Moderate land alteration Yelloi and soil erosion HaC2 Hayden loam 6 to 12% Moderate land alteration Yellol eroded and soil erosion EsD Estherville 12 to 187. Severe land alteration Red sandy loam and soil erosion HaD2 Hayden loam 12 to 18% Severe land alteration Red eroded and soil erosion HcD3 Hayden clay 12 to 18% Severe land alteration Red loam sev.eroded and soil erosion Al Alluvial land © to 2% Severe wetness and Red lit occasional flooding TeB Terril loam 2 to 6% Severe wetness Red lit TeC Terril loam 2 to 6% Severe wetness Red lit Ge Glencoe silty © to 2% Severe wetness Red lit clay loam BuE Burnsville -Hayden Very severe land alteration Blue sandy loams 18 to 25% and soil erosion HaE2 Hayden loam 18 to 25% Very severe land alteration Blue and soil erosion HaF Hayden loam 25 to 4©7. Very severe land alteration Blue and soil erosion- HcE3 Hayden clay 18 to 25% Very severe land alteration Blue sev.eroded and soil erosion Ma Marsh Q to 2% Very severe land alteration Blue li and soil erosion 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, and septic tank drain fields. HaB* HaC2, HaD2, HaE2, HaF, HcD3, HcE3 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 aboi inches thick. The subsurface layer is dark grayish brown loam about 7 inch+ The subsoil is dominantly yellowish brown fires clay loam about 34 inches the underlying material is light olive brown loam. The major building site limitation is slight landscape alteration and erosi+ sediment hazard on the B slopes (2 to 6%), moderate landscape alteration an( sion and sediment hazard on the C slopes (6 to 12%), severe landscape alters and erosion and sediment hazard on the D slopes (12 to 18%), and very severe scape alteration and erosion and sediment hazard on the E and F slopes (18 t In many Hayden areas, water moves through the soil very slowly and basement is a common problem. Septic tank and drain fields have a moderate limitation on the 2 to 12% sloF a severe limitation on slopes over 12%. All slopes have percolation rates c to 75 minutes per inch. When used as foundations for low buildings, they have a moderate limitation: shear strength, moderate shrink -swell potential, medium compressibility, med bearing values, and basement seepage can be a common problem. When used for streets and low-cost roads, they have a moderate shrink -swell tial, moderate susceptibility to frost action, moderately fine textured subs and are found on gently sloping to steep topography. On slopes over 12% the tation becomes severe because of deep cuts and fills. The road maintenance lems also increase as the slope increases, especially from erosion and seeps Esc, ESD Estherville soils are somewhat excessively drained sandy loam sediments comm 15 to 24 inches thick. The underlying materials are limy sands and gravel. The major building site limitation is soil erosion when vegetation is remove When used for foundations for low buildings the limitation is slight and all tors are usually favorable. Septic tank filter fields have a slight limitation on 0 to 6% slopes, modera limitation on 6 to M slopes and severe limitation on slopes over 12%. All slopes have a high hazard of pollution of nearby lakes, streams and wells; percolation rates of less than 10 minutes per inch are common. When used for streets and low-cost roads, all factors are favorable except fq steepness and erosion hazard on slopes over 6%. BuE Burnsville -Hayden Complex - This is a soil complex consisting of Hayden a other well drained loamy and sandy soils. These soils are so intermixed on landscape that separation is not practical. The major building site limitation, septic tank limitation, foundation limi tion, and street and road limitation is 'variable soils' and slopes greater 18%. Al Moderately well drained mixed alluvial soils. These materials are commonly feet or more thick, and are variable in color and texture. They occupy 3 to acre nearly level bottomlands. The major building site limitation is variable wetness. The wetness is dep upon the seasonal high water table, seepage, and the stream flow and water of adjacent streams and drainageways. When used for foundations for low buildings, they have a severe limitation; seasonal water table and occasional flooding is common. Septic tank filter fields have a severe limitation: high seasonal water tab: occasional flooding, possible hazard of pollution of nearby streams, moderal moderately rapid permeability, percolation rates of 20 to 60 minutes per ini When used for streets and low-cost roads, they have variable soil materials high seasonal water table, subject to occasional flooding, moderate to high ceptibility to frost action and low to moderate shrink -swell potential. TeB, TeC Terril soils are moderately well drained loamy soils commonly many feet thi< They occupy 3 to 200 acre long, narrow concave fdotslopes. Slopes commonly from 2 to 14%. The major building site limitation is wetness with the water table at 3 to for short periods during the season. When used as foundations for low buildings, they have a moderate limitation: diem shear strength, moderate shrink -swell potential, medium compressibilit3 medium bearing values, possible high seasonal water table. Septic tank filter fields have a moderate limitation: possible high seasonal table, moderate permeability, possible sidehill seepage, percolation rates c to 75 minutes per inch. When used for streets and low-cost roads, they have a moderate shrink -swell tial, medium textured soil, high susceptibility to frost action, possible hi seasonal water table and sidehill seepage. Ge Glencoe soil consists of depressional and nearly level very poorly drained formed in alluvial sediments and glacial till in uplands. The surface laye black and very dark gray clay loam about- 13 inches thick. The underlying m ial is grayish brown and light olive brown loam. The major building site limitation is severe because of wetness. The Olenc soil is very poorly drained and has a high seasonal water table that range near the surface to a depth of 3 feet. Septic tank drainfields will not function because of the seasonal high ware When used as foundations for low buildings, they have a severe limitation: water table, medium to low shear strength and bearing values, moderate shrii swell potential, and medium compressibility. When used for streets and low-cost roads, they have a high seasonal water t; are occasionally ponded, and have a high susceptibility to frost action, moi shrink -swell potential, and a moderately fine texture. Ma This miscellaneous land type (marsh) includese shallow lakes, ponds and sloe that support aquatic vegetation. Emergent plants such as cattails, reeds, sedges and water tolerant grasses are present. These areas have open water of the year. The soil material is too wet to be classified' but is commonll peaty muck or a loamy mineral soil. Size of the areas ranges from 2 to 100 and occupies closed depressions and borders of lakes and streams. These areas are unsuitable for building sites without excessively expensive lamation work. The accuracy of the soil survey when transferred to a larger scale developm( plan map is related in part to the scale of the plan map and to the accuracy and interval between the contour lines shown on the plan map. For additional soils information, see "Soil Survey - Carver County, Minnesot United States Department of Agriculture, Soil Conservation Service, Novembei The soil investigations, mapping and interpretations ordinarily apply to the upper 5 to 6 feet of soil material. There should be additional onsite iuve€ gation relating directly to the proposed uses before construction is startec fDI_A1! iQEvI&w The "Hesse Farm" preliminary sketch plan is divided into three areas. Area has 18 lots ranging from 4.5 to 8.5 acres in size, Area Two has 9 lots rangi from 5.5 to 8.5 acres in size and Area Three has 20 lots ranging from 3.8 tc 7.4 acres in size. The steeper Hayden soils are colored red (12 to 18%) and blue (18 to 40%). red lined area on the map outlines the Alluvial, Terril and Glencoe soil ar These soils have a high seasonal water table. Therefore, home site locatio should be made very carefully to avoid excessive landscape alteration, soil erosion, and sediment damage, septic tank and drainfield failures, and wet meats. It is very difficult to construct a septic tank and level drainfield on slo] over 12% and hillside seepage of effluent is a common problem. Home site location and septic tank drainfield location are the two primary I lems on this plan. The plan should show the exact location of each of the l that will be built, including the well, septic tank and drain€ield. Each 11 should provide for a minimum home site of 1/2 acre to allow room for a well house, and a standard septic tank and drainfield. The green and yellow cols on the map indicate Hayden soil with slopes under 12%* However, some of th+ Hayden soils in these areas can a very slow permeability rate, There are five gully heads on the property located on the East side of the i I have numbered these in red: 1, 29 3, 41 5. These should be investigated i stability and care should be taken not to divert additional runoff water in1 then. The following lots apparently do not have a minimum 1/2 acre home site area accommodate the house, well, septic tank and drainfield. They either have greater than 12% or they are on soils with a high seasonal water table. Are Lots 8, lit 12, 13 and 17; Area 2 - hots 2, 59 b, 7 and 8; Area 3 - Lots 10, and 18 and in addition, Lots 7, 8 and 9 are pretty close to the minimum size Lots 13 dnd 14 could have long and possibly poor access if the homes are bui the back of the lots. The 13 acre pond in the North Central part of Area 1 was designed by the Sol Conservation Service in June of 1970, based on agricultural hydrology, and constructed in 1971. I do not believe the low density housing proposed will affeet the runoff characteristics of the site; however, the emergency spills lying 100 feet Northeast of the principle pipe spillway should be maintainer made part of the road design that crosses the principle pipe spillway. We believe that slopes over 18% (blue on map) should be maintained in a natt cover of grass, shrubs, and trees, and these areas should be improved, plant and managed as protection or open space. The following conservation practices contribute to good land use and better housing developments: 1. Maintain the natural surface drainage pattern, improve and beautify it F possible. 2. Steep slopes, creeks, waterways, flood plain areas should be managed fot open space for natural beauty and/or for park purposes. 3. Save existing trees of good quality and maintainn the grass and shrubs o steep slopes. 4. Keep land gradingp landscape alteration to a minimum. 5. Save and stock pile topsoil for use during final grading. 6. Complete gradingg restore topsoil and seed to grass as soon as possible the building process and seed all exposed areas within 30 days after gr, 7. Plan streets and driveways to fit the contour of the land. 8. Complete surfacing of roads and driveways as quickly as possible. Attached: Site Plan Review With Soil Mapping Units Colored to Show Buildinj Site Limitations and Color Key