Agenda - Council - 04/23/2013 - Laserfiche WebLink

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move though the greenway. This activity has occurred --the greenway corridor has been developed as The Draw park and wetland restoration/creation has taken place. The City will continue to work to implement these measures. Blanding's Turtles Strategies outlined for Wildlife Mitigation generally apply to Blanding's turtles. The City will continue to work to implement these measures. Item 12 Mitigation Element. Wetland Sequencing - Minnesota Rules 8420, also known as the Wetland Conservation Act (WCA), requires specific steps (sequencing) be taken when evaluating mitigation for unavoidable wetland impacts. This activity has occurred and will continue to occur. The wetland mitigation plan has been modified from the original AUAR concept, but has been permitted in compliance with WCA and this AUAR update reflects those changes. Stormwater outfall to the Mississippi River: • Reduce Frequency of Stormwater Discharge, Lower Magnitude of Peak Flow Rates: The project incorporates a variety of strategies to lower increases in stormwater rate and volume. While all stormwater conveyance features are designed to accommodate the 100-year runoff event without taking infiltration into consideration, on -site retention and infiltration can be incorporated at multiple scales into the development during the detailed design phase for smaller storm retention. Peak flow rates for the 100-year, 24-hour runoff and 100-year, 10-day snowmelt events are 25.1 cfs and 25.3 cfs respectively. The City will continue to work to implement this measure. • Oversize Culvert and Reduced Slope at Outfall: The last section of culvert will be enlarged from 21- inches to 36-inches and include an apron and rip -rap to lower velocities and dissipate the energy at the discharge point. This will minimize the potential for scour and erosion. This item has been completed. The outlet to the Mississippi River was installed by the city in 2009. • Directional Boring to Install Culvert: If possible, the culvert will be placed within the river bank by directional boring rather than an open cut. This will reduce the need to remove shoreline vegetation and will minimize the area of disturbance. Erosion control measures will be implemented where soil is disturbed. All disturbed areas will be replanted to native trees, shrubs, grasses and forbs and if appropriate, a temporary cover crop will be established. This item was completed by the City in 2009. Item 13 Mitigation Element. Because the COR site is within a DWSMA, special precautions are needed to protect groundwater resources. To make sure this occurs, any discharge of runoff into an area dedicated to infiltration will be pre-treated through such practices as particulate settling, vegetative filtration, skimming, installation of compact, sub -grade treatment (ex. catch basin inserts, cyclonic separators, filters), and various types of pre-treatment soil filtering systems. These practices will be routinely maintained and inspected to make sure these pre-treatment practices do not provide a pathway for contamination of groundwater. Areas that are potential major sources of contamination ("hot -spots") will be identified during construction and special precautions added. These areas would include any location where pollutant spills are more likely to occur (service stations, public works/police/fire fueling operations, significant chemical storage). The City has completed a Wellhead Protection Plan, which was Alternative Urban Areawide Review Update The COR (formerly Ramsey Town Center) City of Ramsey, MN Landform Project No. RAM12015.000 4