City Council Workshop - Storm Water Management - There will be a City Council Workshop in the Council Chambers on Monday, April 7 at 6:00 to discuss several aspects of the City's Storm Water Management Program. Topics that will be discussed include implications of the recently issued storm water discharge permit, the draft Storm Water Management Plan, several planned storm water related projects and status of the storm water fund. This will be an open meeting and the public is encouraged to attend. A Commentary article on the City's storm water program was also published in the March 15 issue of the Republican Eagle.
Infrastructure Maintenance and Permit Requirements Drive City’s Storm Water Utility Program Needs
Managing storm water has become more complicated over the last 20 years, and will continue to do be so into the future. In the past, the objective was to collect and convey runoff into the river as quickly as possible. The goal was to eliminate flooding and water quality was not considered. Much of our older storm water infrastructure was constructed with this goal in mind. In 1988, the Environmental Protection Agency began to formalize storm water quantity and quality requirements. Much of the storm water infrastructure constructed since 1988 includes measures to reduce the amount of water discharged, as well as the concentration of pollutants like phosphorus and sediment. Our storm water infrastructure includes 55 miles of sewers, 4 miles of tunnels, 4 miles of concrete flumes, 2400 catch basins, 62 treatment ponds and 180 outfalls. Storm water management in Red Wing is operated as a utility and is becoming as involved as the water and wastewater utilities. Revenue is generated through the storm water fee included in the monthly utility bill.
The Minnesota Pollution Control Agency recently reissued the City’s Municipal Separate Storm Sewer System (MS4) permit. This permit allows the City to discharge storm water under the terms and conditions of a general statewide permit which is designed to reduce the amount of sediment and other pollution that enters surface and groundwater. Permittees are required to develop a Storm Water Pollution Prevention Program (SWPPP) that utilizes documented Best Management Practices (BMPs) to accomplish this goal. The best management practices are organized into six categories, namely: Public Education and Outreach; Public Involvement and Participation; Illicit Discharge Detection and Elimination; Construction Site Runoff Control; Post-Construction Runoff Control; and Pollution Prevention and Good Housekeeping. Documented enforcement procedures are also required.
The storm water permit applies to all storm water discharges within the city, whether they originate in a conventional sewer, a roadside gutter, a roadside ditch, a ravine or overland flow. Run-off flow control and treatment measures may be necessary in the rural areas of the City as well as the more urban areas. In addition, the permit covers storm water drainage from the common areas, including parks, streets and public facilities. Because of this, the storm water fee is assessed to all parcels in the city limits.
Many of the same environmental attributes that add to the quality of life in Red Wing also impact the storm water program, significantly increasing the overall cost. Bullard Creek, Hay Creek and Spring Creek are designated trout streams and have stringent requirements that are intended to minimize nutrient and temperature impacts. The Cannon River is designated as an Outstanding Value Resource Water and also has stringent discharge limitations. The Mississippi River has impairments for nutrients and sediment, which will result in future constraints for storm water discharges. The hills and bluffs also impact storm water facilities. Run-off from developed areas on the hillsides will need to be conveyed very quickly, requiring large capacity sewers, and will minimize the time available for treatment.
Storm water management is a combination of maintaining the existing infrastructure, (in some cases over a hundred years old) incorporating zoning and other regulatory requirements to reduce storm flow and the resulting contaminates, and providing any additional infrastructure necessary to meet the new, more stringent requirements. The City is working with an engineering consultant to develop an updated Storm Water Management Plan. This plan includes computer simulations that predict storm water volumes, flow rates and water quality, and will be used as a tool to prioritize our activities to make sure we have the necessary conveyance capacity and can remain in compliance with the discharge requirements of our permit in the most cost effective manner. The Management Plan is going through final revisions and will be presented to the City Council at a workshop on Monday, April 7th. The plan will be placed on the City’s website after it is adopted by the Council.
Several significant storm water infrastructure projects are planned for 2014. The most significant is the repair of a segment of one of the major storm water tunnels in the downtown corridor. Public Works recently completed a detailed engineering assessment of the tunnels, and several areas were found to require repairs that were rated as urgent, which by definition means “structural defect requiring immediate attention”. The project planned for this spring will replace segments of the roof on the tunnel on Fifth Street between Plum and East Avenue, and through the East Avenue and Fifth street intersection. The estimated cost for this project is $365,000. Other similar scope projects will need to be carried out on an annual basis until the most critical sections are all addressed. Another project that is planned for this summer is to address the ditch erosion and reduce the amount of sand that is washing into Hay Creek from one of the tributary ravines. This project will also cost several hundred thousand dollars. Photographs from both of these projects can be viewed on the city’s website.
The City is committed to protecting the natural environment that we all appreciate, and to remain in compliance with the regulatory requirements that govern our storm water discharges. We all have a role to play in this effort. This can be as simple as being careful not to blow or rake leaves and grass clippings into the gutter and utilizing rain barrels to regulate the rainwater from our rain gutters. While these individual efforts may seem small and insignificant, they are important in aggregate, and will lead to more effective and less costly storm water management.