WRAPS Terrace Policy

1. WRAPS Terrace Policy KDHE – Watershed Management Section September 15, 2016 Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

2. Terrace Policy Discussion • WRAPS Mission • Gradient vs. Tile Outlet Terraces • Load Reduction of Terraces • Cost/Benefit of Terraces • WRAPS Policy on Terraces Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

3. WRAPS Mission • WRAPS Mission is to improve water quality degraded by non-point source pollution, delist impaired waters, meet water quality standards, and restore designated uses for all water bodies in Kansas • Total Watershed load reduction is the goal, so efficiency of each practice is crucial Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

4. WRAPS Mission • Not Traditional Cost Share Program • Not Farm Bill – Clean Water Act • Focus on Water Quality Goals • Educate, Change Behavior Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

5. Terraces • All Terraces break up slope length • Gradient Terraces channel water to slow runoff and carry it to a stable outlet, i.e. Grassed Waterway • Tile Outlet Terraces collect water and store it until it can release through a stable outlet, i.e. Pipeline Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

6. Terraces • WRAPS resource concern is water quality as it leaves the field • Gradient Terraces have Grassed Waterway to treat runoff in field • Tile Outlet Terraces have storage where some sediment settles out Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

7. Terraces • Water Quality Questions remain about how much sediment settles out at certain retention times in Tile Outlet Terraces and what Nutrient reduction is achieved Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

8. Terraces with Secondary Treatment • We do know that secondary treatment such as a wetland does improve water quality • Study by KU in Upper Wakarusa WRAPS shows • The pilot wetlands removed 57%-83% of the total TSS, and were particularly effective at treating high-TSS runoff. • Total phosphorus removal ranged from 32-38% at sites 1 and 2 to 53% at site 3. • Total nitrogen removal was highest at site 3 (53%), lowest at site 2 (17%), and highest at site 3 (53%). Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

9. Load Reduction of Terraces • “S” in Revised USLE is slope length factor, However Technically “S” cannot be changed in the equation, we reduce the support practice factor “P” by 30% for Terraces • “The effect of runoff interceptors (diversions, terraces) is taken into account by how these practices reduce slope length and cause deposition in the channels created by these interceptors” ( https://www.ars.usda.gov/southeast-area/oxford-ms/national-sedimentation-laboratory/watershed-physical-processes-research/docs/revised-universal-soil-loss-equation-2-how-rusle2-computes-rill-and-interrill-erosion/ ) Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

10. Load Reduction of Terraces Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

11. Cost/Benefit of Terraces • Gradient Terrace example 8253 ft. of Terraces installed, cost-share paid was $9,656 ($1.17 per linear foot) protecting 48 acres with 27 tons of sediment load reduction • Therefore Cost/Benefit on this practice was $357.63 per ton of sediment reduced Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

12. Cost/Benefit of Terraces • Tile Outlet Terrace example 3884 ft. of Terraces installed, cost-share paid was $10,000 ($2.57 per linear foot) protecting 20 acres with 21 tons of sediment load reduction • Therefore Cost/Benefit on this practice was $476.19 per ton of sediment reduced Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

13. Cost/Benefit of Terraces • For Comparison, Cover Crop load reduction from a practice in same grant as tile example • Cost-share was $2,920 to plant 87 acres with Cover Crops ($33.56 per acre) with 166 tons of sediment reduced • Therefore Cost/Benefit on this practice was $17.59 per ton of sediment reduced Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

14. Cumulative Effect of Terraces on WRAPS • 2013 WRAPS paid $401,203 on terraces • Cost/Benefit of $116 per ton of sediment • WRAPS paid $14,124 on tile outlet terraces • $979,358 allocated through WRAPS for all needed BMPs • 2014 WRAPS paid $452,655 on terraces • Cost/Benefit of $151 per ton of sediment • WRAPS paid $148,617 on tile outlet terraces • $1,078,273 allocated through WRAPS for all needed BMPs • 2015 WRAPS paid $930,625 on terraces • Cost/Benefit of $156 per ton of sediment • WRAPS paid $307,850 on tile outlet terraces • $1,092,959 allocated through WRAPS for all needed BMPs 41% 42% 85% Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

15. Cumulative Effect of Terraces on WRAPS • Only 9 out of 32 WRAPS Projects are meeting sediment goals • Other pollutant goals not being met due to funding limitations Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

16. Fixing Gullies • Tile outlet terraces can be preferred method to mitigate classic gullies • Gully load reduction based on width, depth, and lateral recession rate of gully – need these measurements each time • Must be reported as gully stabilization practice • Must meet cost/benefit target set by SLT Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

17. Fixing Gullies • $10,000 cost to fix gully top width 15 ft, bottom width 8 ft, depth 6 feet, 300 ft long, back cutting for 5 years = 176 tons of sediment load reduction • Cost benefit $10,000 / 176 tons = $56.81 per ton of sediment Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

18. Fixing Gullies • $10,000 cost to fix gully top width 10 ft, bottom width 4 ft, depth 4 feet, 150 ft long, back cutting for 10 years = 18 tons of sediment load reduction • Cost benefit $10,000 / 18 tons = $555.55 per ton of sediment Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"

19. WRAPS Policy on Terraces • Max cost-share on any terrace is $1.00 per linear foot – no other components may be funded separately • Terraces must be 35 years of age and nonfunctional • No gradient terrace outlet conversion to tile outlet if waterway can be rebuilt • Terrace cost-share only eligible on continuous no-till fields or conversion to continuous no-till operation (NRSC 640) • Encourage other practice types that reduce sediment and nutrient loading such as cover crops, nutrient management plans, etc. • Tile terraces on TMDL streams will increase design holding time from 8 hours to at least 12 hours • Must use bubble up riser at outlet • Outlet must be 30 feet from a receiving stream and area between outlet and stream must be permanently vegetated Our vision is 'healthy Kansans living in safe and sustainable environments'. The state belongs to all of us - "Kansas Don't Spoil It"