Checkout of Grassed Waterways Beth E. Clarizia, P.E. Agricultural Engineer

Standard Requirements ► Waterways designed to handle a minimum capacity ► Must have a stable outlet ► Flow velocities targeted for a reasonable range, but kept below 5 fps ► When design velocity >3 fps, ECB is required ► Seeding dates: 3/1-5/15 or 8/1-9/30

Checkout Requirements ► Measured constructed length ► Center and low bank shot every 100 feet ► Full cross section every 300 feet

Design The whole design storm must fit inside the designed flow section, and the velocity when this design section flows full cannot exceed 5 fps. The whole design storm must fit inside the designed flow section, and the velocity when this design section flows full cannot exceed 5 fps.

Cross-sections  Must show that water drains to the waterway.

Cross-sections  Can assume a tenth or two of depth of fill along the sides, but be careful.

Survey methods Use actual, surveyed cross sections and centerline points. Do not interpolate from a generated contour. Use actual, surveyed cross sections and centerline points. Do not interpolate from a generated contour.

Waterway Inlets and Outlets  Upstream and downstream ends must: ­ grade out to existing stable ground ­ meet a structure ­ If rock outlet pad is at downstream end, include in waterway checkout

Alternative designs ► Not eligible

Seeding  Indicate whether you have done the seeding or not above your signature on the survey notes page  If installing ECB, fill out ECB installation report (you should always be confirming seeding if installing ECB)

Rates ► Grassed Waterway = $320 per waterway

Questions ???