Stormwater Pond Maintenance

Why are Stormwater Ponds important?

Stormwater ponds are designed to treat stormwater runoff and improve water quality.  The stormwater ponds detain stormwater runoff for an extended period of time, allowing for the suspended pollutants to settle down to the bottom of the pond and prevent them from entering our streams and rivers.  Stormwater ponds also help prevent flooding by providing temporary storage of runoff and hold the water for a short period of time.  Within the City of Owatonna, 20 public stormwater ponds and 40 private stormwater ponds exist. 

Maintenance and Responsibility

Stormwater ponds, whether they are located on a a commercial or residential lot may be the responsibility of a business, the City, individual homeowner, or a homeowner association.  Proper pond maintenance is very important and aids in the prevention of many problems that may arise from having a poorly maintained stormwater pond.   As a landowner, the responsibility of maintaining these stormwater ponds not only helps you, but the whole community around you.  If the responsibility is unknown, please contact the Stormwater Manager.  A regular maintenance program should be must be maintained and used to ensure that pond(s) continue to function properly.   A maintenance program should consist of three phases:

  1. Regular Maintenance-remove trash surrounding the pond, repair embankments or spillways, repair inlet and outlet pipes, remove large vegetation, and stabilize areas below the pipe outlet experiencing erosion.
  2. Annual Inspection-assess weed growth, effectiveness of weed management program, integrity of pond's control structure, and damage after major storm events.
  3. Periodic Dredging-verfiy if sediment has filled in the pond, remove excess sediment from pond with dredging equipment, consider dredging roughly every 10 years.

Corrective Action

In not properly maintained, stormwater ponds will not function correctly and can cause pollution to our streams and rivers.  As required by the Stormwater Ordinance, "all stormwater management facilities hall have a plan of operation and maintenance that assures continued effective removal of pollutants carried in stormwater runoff".  If stormwater ponds are identified as inoperable, faulty, or in disrepair, the responsible party will need to take immediate action to correct all issues.