Surface Water Management Plan The city adopted the surface water management plan as part of the 2030 Comprehensive Plan in January 2010. Implementation requirements of the surface water management plan call for an update to the city’s stormwater management standards and ordinance to ensure all requirements of the plan are being met.
Stormwater Management Ordinance & Standards In the spring of 2015 the city updated its stormwater management standards to meet the requirements of the latest Municipal Separate Storm Sewer System (MS4) permit administrated by the Minnesota Pollution Control Agency (MPCA). The new MS4 permit was used as a guide for a new stormwater ordinance, which was adopted by the City Council on June 6, 2015. Following is a summary of the ordinance:
All new development and redevelopment on projects which encompass 0.5 acre or more of disturbed area or 5,000 square-feet or more of new impervious surface will be evaluated based on the new stormwater requirements.
Runoff rates shall not exceed the pre-project runoff rates for the 2-year, 10-year, and 100-year critical duration storm events.
Total suspended solids will require treatment through infiltration practices for runoff volumes of at least 1.1 inch over all new impervious and redevelopment impervious portions of a project.
No person shall throw, drain, discharge into the municipal separate storm sewer system any pollutants or waters containing any pollutants other than stormwater.
Coal tar sealers are prohibited (refer to section below).
Ban on Coal Tar Sealers
The use of coal tar sealers on asphalt driveways is a common practice. Coal tar sealant products contain polycyclic aromatic hydrocarbons (PAHs), which are a group of organic chemicals formed during the incomplete burning of coal, oil, gas, or other organic substances. Scientific studies have demonstrated a relationship between the use of these products on stormwater runoff and certain health and environmental concerns.