03-24-2009 Council Work Session Packet

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r , CMP Part 3A. Environmental Protection Plan ponds); (4) applying chemicals to precipitate out the orthophosphorus (alum treatments); (5) encouraging growth of certain aquatic plants; and (6) design of outlet structure to provide extended detention of large runoff events. Whether each of these enhancements can or should be incorporated is dependent on the desired level of control and other site specific conditions. Constructed wetlands have potential benefits as well as drawbacks. Additionally, the cost of constructing storniwater ponds and storm sewer systems is enormous compared to the cost of wetland preservation. Ve�etated buffers, �reen strips adjacent to hard surfaces. permeable pavements that incorporate runoff treatment features, and rain �ardens are just some of the additional tools available for supplementin� runoff mana�ement. �e-v� �Nutrient management technologies such as NURP ponds or alum treatments will give Orono an added tool to manage runoff from rural densities, but Orono cannot and will not rely solely on man-made systems for preserving water quality. ORONO'S NATURAL RESOURCES 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. Steep slopes and numerous glacial depressions add interest to the City's landscape but cause development limitations. The soils in the City of Orono (Map 3A-3 - use soils map from Orono NRI)) originated from drift materials deposited by meltwaters of the glaciers. Due to the range in type and location of deposited materials, the composition of the soils is complex and highly varied. 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. Orono's native vegetation is �c .,^--;�a ^� ;*c '^ra ''^r-�c primarily woodland interspersed with localized areas of wet prairie marshlands. r'r^^^ �^a r �'�o Northern Orono and many areas along Lake Minnetonka's shore, contain vestiges of Minnesota's Big Woods with hardwood forests of oak, maple, elm, and basswood. Much of these have been thinned into scattered stands, as shown on Map 3A-4, but major forests remain in north central and north east Orono, especially around Lydiard Lake and in the Mn. DNR's Wolsfeld Woods and Wood Rill nature areas. In addition, 100 year old settlements have by now added mature stands of various evergreens and other decorative trees and shrubs. City of Orono CommuniTy Management Plan 2008-2030 Page 3A-8