08-24-2015 Council Packet - Laserfiche WebLink

Home Search

Hydrology will continue to be provided to the wetland area (created and restored) via adjacent biofiltration basins. These biofilration basins collect and treat water from the surrounding impervious surfaces created by the fire station and roadways and discharge to the mitigation area. The hydrology provided will be consistent with that of Type 2 wetland. The wetland mitigation area excludes a small area of wetland adjacent to the culvert under the entrance along Birch Street. This area will be utilized to provide rate control to the downstream wetland east of the entrance. Buffer A minimum 25 foot buffer easement will be placed around the restored and created wetland. The buffer is proposed to be seeded with seed mix 35-241 at a rate of 36.50 Ib/ac. Broadcast Seeding If the soil within the proposed planting area is deemed too compact for to allow for water and roots to penetrate into the ground, then the area should be tilled to allow for penetration. Every effort shall be taken to obtain uniform distribution over the seeded area. To offset the fact that native seeds vary in size and weight, the seed mix should be mixed with an inert material for broadcasting. Slightly moistened sand, sawdust, or peat moss should be used as the inert material since they would stick to the seeds resulting in a more even spread, make the seeded area more visible, and help to extend small amounts of seed. Before broadcasting of the seed commences the seed will be divided into two parts. Once divided, broadcast the first half of the seed over the entire area while walking in one direction (e.g. north south). Once the first half is distrusted broadcast the second half walking perpendicular (e.g. east west) to the first pass. This method will ensure even coverage of the ground and will prevent running out of seed before the entire area is seeded. Seedbed Firming The City shall firm all seeded areas after seeding and prior to mulching. The soil firming shall be done with a roller, cultipacker or other approved soil firming equipment. On slopes too steep to operate mechanical equipment, the seed shall be covered by hand raking or other approved means prior to mulching. Soil firming or seed covering shall occur immediately after seeding. Mulching All wetland restoration areas shall be mulched with Mn/DOT Type 3 MCIA certified mulch at an application rate of 1 ton/acre. The City shall spread by mechanical means (preferably a blower) to provide a uniform distribution at the target application rate specified. If poor mulch distribution occurs, the Contractor will be required to re - mulch areas where coverage is too light and remove the excess where coverage is too heavy as determined by the engineer. Mn/DOT Type 3 Mulch —Type 3 mulch shall consist of clean grain straw (i.e., oats, wheat) that is certified by the Minnesota Crop Improvement Association (MCIA) to be free of noxious weed seeds, seed bearing stalks, and/or other reproductive propagules as defined by rules and regulations of the 3