City of Rapid City

Excerpts from Rapid City Stormwater Management Plan

1.7 Maintenance

All temporary and permanent erosion and sediment control practices shall be maintained and repaired by the owner during the construction phase as needed to assure continued performance of their intended function. Sediment traps and basins will require periodic sediment removal when the design storage level is half full. All facilities shall be inspected by the owner or owner’s representative following each heavy precipitation or snowmelt event that results in runoff. As part of the narrative report, the professional engineer preparing the plan shall submit a schedule of planned maintenance activities for temporary and permanent erosion and sediment control measures. The schedule shall be consistent with the level of maintenance required for the control measures proposed It the plan.

Suggested maintenance plans:

Grass Buffer: lawn mowing and lawn care should be performed on a routine as needed basis. Irrigation and litter removal as needed. Inspections occur annually and after major storms with more than 0.75 inch in precipitation.

Grass Swale: Lawn mowing and lawn care as needed. Debris and litter removal no less than two times a year. Sediment removal routine, as needed by inspection. Grass reseeding and mulching as needed by annual inspection. Annual inspection.

Porous Landscape: Lawn mowing, debris and litter removal, and vegetative care routine and depending on aesthetic requirements. Landscaping removal and replacement every 5 to 10 years depending on infiltration rates. Routine biannual inspection of hydraulic performance.

Extended Detention Basin: Lawn mowing, lawn care, debris and litter removal, routine. Erosion and sediment control periodic and repair as necessary based on inspections. Structural repair as needed based on regular inspections. Nuisance control and sediment removal as needed. Inspections occur annually, includes hydraulic and structural facilities.

Sand Filter Detention Basin: Debris and litter removal routine. Landscaping removal and replacement every 2 to 5 years. Scarify filter surface once per year or when needed to promote drainage. Sand filter removal evert 2 to 5 years, when it takes more than 24 hours to empty a 3 foot deep pool. Expect to clean out forebay every 1 to 5 years. Routine-biannual inspection of hydraulic performance, one after a significant rainfall.

Constructed Wetlands: Lawn mowing and lawn care, debris and litter removal, routine and before annual storm seasons. Sediment removal every 10 to 20 years as needed by inspection. Aquatic plant harvesting nonroutine until further evidence indicates such action would provide significant nutrient removal. Perform once every 5 years or less frequently as needed. Inspections at least once a year, preferable during a rainfall event resulting in runoff.

Links

Stormwater Permits Page

Stormwater Management Plan

Rapid City Stowmwater Quality Manual