07-22-1985 Council Packet - Laserfiche WebLink

Home Browse Search

Zoning File #852 July 19, 1985 Page 3 The wildlife pond involves the alteration of 1.3 acres of a 2.6 acre protected wetlands. The alteration involves the removal of 5,500 cubic yards of fill to be trucked off the si`e for disposal. Planning Commission advises that Council require the trucking not only off the site but out of Orono. Dr. Hanson on the other hand, notes that as long as the spoils are removed from the watershed of the wetland that is sufficient. He strongly recommends that these rich spoils be used in place of fertilizer by farmers. He claims the nutrients in the spoils will held restore depleted farm lands. The wetland is predominatly a type 3 or cattail - sedge wetlands and the remaining portion a type 6 or shrub swamp. Artifical pond or open water are type 5. Type 3 being the most efficient nutrient trap or treatment provider and type 6 the least effective. Both Dr. Hanson and Joel Settle of the U.S. Soils Office claim no signi 'icant impact on water quality. Hanson prefers open water areas as nutrient traps finding mature marshes and wetland releasing as many nutrients as enter the wetland. The sides of the wildlife pond nearest the outlet have 7:1 slopes providing a shallo,,. water area and a better habitat for emergent vegetation. This fringe vegetation area will provide a natural buffer area of approximately 50 feet in width between the open water areas and the outlet. The vegetation buffer will also serve as a filter strip for runoff from formal pond. A skimmer has been provided at outlet to remove debris prior to discharge to Brown's Bay. Kopishke has advised that the skimmer will be constructed of timbers treated with Chromated Copper Arsenate. Dr. Hanson advises that Copper and arsen are most toxic and the City should recommend timber treated with penta. The proposed pond satisfies the wildlife constuction standards of the DNR - varied bank slope ratios of 7:1 to 3:1 with island areas in midst of open water. The upper watershed that drains into this 2.69 acre wetland (see Exhibit H) consists of approximately 100 +/- acres developed at 2 acre rural standards. There is approximately 23 +/- acres of upland wet- lands within that watershed. The upland wetlands appear to be equally divided between shrub swamp (type 6) and cattail sedge (type 3). Note once again, Dr. Hanson's comments concerning the positive effects of open water areas within wetlands. Review of Issues to be Addressed by City: Water Quality 1. Type of Wetlands 2.69 acres - major portions type 3 other type 6 - only open water .07 acres is on railroad right-of-way. Applicant proposes conversion of type 3 to type 5 - open water area of approxi- mately 1.3 acres with island areas included. Settlers 6 Hanson claim no appreciable effects.