Orono Community Management Plan 2020-2040

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CMP Part 3A. Environmental Protection Plan City of Orono Community Management Plan 2020-2040 Part 3A, Page 7 Vegetated buffers, green strips adjacent to hard surfaces, permeable pavements that incorporate runoff treatment features, and rain gardens are just some of the additional tools available for supplementing runoff management. Nutrient management technologies such as NURP ponds or alum treatments will give Orono an added tool to manage runoff from rural densities, but Orono will not rely solely on man-made systems for preserving water quality. ORONO’S NATURAL RESOURCES Soils Orono's land forms are highly varied as the result of four separate glacial scourings. Surface features include islands, peninsulas, narrow land bridges, the lakes, bays and marshes, and a few shallow outwash basins. The highest elevations range from about 1060 feet above mean sea level in the northern part of the City down to the normal water level of Lake Minnetonka at elevation 929.4 MSL. The soils in the City of Orono (Map 3A-3) originated from drift materials deposited by meltwaters of the glaciers. Generally, the soil types consist primarily of clay and loam materials on the uplands and organic, wet materials in the lowland areas. Consequently, the ability of each soil type to adequately accommodate development varies considerably in Orono. Careful examination of each site is needed to determine the most appropriate land use for individual properties. Map 3A-3 references 7 different classes of soils. These classes are: Group A soils have a high infiltration rate and low runoff. These soils consist of deep, well drained sands or gravelly sands and have a high rate of water transmission. Group B soils have a moderate infiltration rate. This group consists chiefly of deep well drained soils with a moderately fine to moderately coarse texture and a moderate rate of water transmission. Group C soils have a slow infiltration rate. This group consists of soils with a layer that impedes the downward movement of water or fine textured soils and a slow rate of water transmission. Group D soils have a very slow infiltration rate and high runoff potential. This group is composed of clays that have a high shrink-swell potential, soils with a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is placed in group D because of a high water table it may be assigned to a dual hydrologic group: A/D, B/D, or C/D. The first letter of the pair represents the soil’s group if drained and the D represents the natural condition.