Stormwater Addendum

BMP 32 Check Dams

Caution must be taken when establishing the check dam heights. If the check dam is too high, excessive pooling of run-off may occur.

Receive prior approval of the Valley County Engineer before applying this BMP.

BMP 36 Silt Fencing

Maintenance: Remove the sediment when it reaches one-half the height of the silt fence or when the silt fence is no longer functioning properly. In addition, sediment should be removed before winter freeze (mid-October).

BMP 11 Use of Alternative Surfaces

Use caution when applying this BMP, freeze thaw cycles may make the effectiveness of this BMP inadequate.

BMP 1 Biofiltration Swale

(vegetated swale)

Limitations: The minimum water table for Valley County is 3 feet.

BMP 5 Compost Stormwater Filter

BMP is limited in treatment of ortho-phosphorus. Recommend using BMP in conjunction with another phosphorus reducing treatment.

BMP 7 Media Filter

BMP is limited in treatment of ortho-phosphorus. Recommend using BMP in conjunction with another phosphorus reducing treatment.

BMP 9 Infiltration Basin

Note: If site already has an infiltration basin, this may be a very desirable BMP for Valley County.

BMP 10 Porous Pavement

Use caution when applying this BMP. Freeze thaw cycles might affect the efficiency of the BMP.

BMP 17 Wet Vault/Tank

Use caution when applying this BMP. The design parameters require significant consideration for the applicability of this BMP in Valley County. Use in conjunction with BMP 18, and receive prior approval of the Valley County Engineer.

BMP 18 Oil/Water Separator

Maintenance: Oil/Water Separators should be cleaned out frequently to keep accumulated oil from escaping during storms. As a rule of thumb, they should always be cleaned by mid-September to remove material that has accumulated during the dry season, and again after a significant storm.