Arid Southwest BMP - 91 -

Sloped Drain POLLUTANTS ADDRESSED: Sediments

DESCRIPTION: A sloped drain is a pipe to convey water from one elevation to a lower one without erosion. LOAD REDUCTION MECHANISM: Sediment Reduction – Because the water conveyed by the drain does not flow directly over the land, erosion is prevented and thus sedimentation does not occur. POTENTIAL TREATMENT AREAS: Agricultural Lands Developed Lands

ALTERNATIVE MANAGEMENT MEASURES Detention Basin Erosion Control Fabric Irrigation System, Tailwater Recovery PERMITTING REQUIREMENTS: Contact county representative LAND USE CLASSIFICATION: Construction sites Agricultural lands Mining areas ADDITIONAL BENEFITS: Water is directed to areas of need.

Arid Southwest BMP - 92 -

Sloped Drain POLLUTANTS ADDRESSED: Sediments

Level 300: MILD ENGINEERING LOAD REDUCTION POTENTIAL:

LOW MEDIUM HIGH ESTIMATED TIME FOR LOAD REDUCTION:

IMMEDIATE MONTHS- > 2 YEARS 2 YEARS EXPECTED MAINTENANCE:

LOW MEDIUM HIGH ESTIMATED COST:

LOW MEDIUM HIGH PLANNING AND IMPLEMENTATION: Sloping drains should be engineered with enough capacity to carry expected flows. If not, water will flow around them creating erosion and threatening the drain. Inlets should regularly be cleared of debris.

Riparian Planting Zone: Bank, Overbank and Transition Zones. SOURCES OF ADDITIONAL INFORMATION: TMDL Water Quality Study of the Virgin River Watershed, submitted to Utah Department of Environmental Quality, Division of Water Quality. http://www.waterquality.utah.gov/TMDL/Duchesne_River_Watershed_TMDL.pdf