Checkout of Grassed Waterways

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

2. 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

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

4. 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.

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

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

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

13. 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

14. Alternative designs • Not eligible

15. 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)

16. Rates • Grassed Waterway = $320 per waterway

17. Questions ???