1. Stormwater Management on the U.S. Virgin Islands Sara Delaney Joshua Faulkner Ian Tse Dave Wang Dave Wang Stephanie Wedekind

2. Motivation Erosion from stormwater runoff was becoming big problem for homeowners Erosion from stormwater runoff was becoming big problem for homeowners Residents went to the U.V.I. for assistance and the U.V.I. came to us for help Residents went to the U.V.I. for assistance and the U.V.I. came to us for help Potential environmental, economical, and developmental problems down the line if nothing is done now Potential environmental, economical, and developmental problems down the line if nothing is done now

3. Motivation (cont.) Steep slopes and shallow top soil promote erosion Steep slopes and shallow top soil promote erosion Government does not have enough resources to pave the state roads, which are currently unpaved and contribute heavily to the erosion Government does not have enough resources to pave the state roads, which are currently unpaved and contribute heavily to the erosion Homeowners and their homesites have priority right now Homeowners and their homesites have priority right now Must find a way to help them

4. Key Design Objectives Comparison/analysis of potential stormwater control methods in regards to established criteria Comparison/analysis of potential stormwater control methods in regards to established criteria Successful solution/design for a selected U.S. Virgin Island homesite Successful solution/design for a selected U.S. Virgin Island homesite Economic cost analysis of construction and materials Economic cost analysis of construction and materials

5. Outline Mission Mission Background information Background information Tasks Tasks Progress Progress Summary of work this semester Summary of work this semester Plans for the future Plans for the future

6. Mission University of the Virgin Islands Cooperative Extension Service, has been addressing the needs of the community since 1972 by defining and solving problems through research and University of the Virgin Islands Cooperative Extension Service, has been addressing the needs of the community since 1972 by defining and solving problems through research and providing quality services.

7. Background Problem : Erosion! Problem : Erosion! 250 250-390 tons/year into Fish Bay watershed from unpaved roads alone (Ramos, 2003)

8. Source of Problem: Rain Rain Developed Land Developed Land Exposed Soil Surfaces Exposed Soil Surfaces Sediment Movement Sediment Movement Contamination of Bays Contamination of Bays

9. Approaches to Problems Lack of regulations or infrastructure Lack of regulations or infrastructure Concentrate on solution for homeowners to implement Concentrate on solution for homeowners to implement

10. Specific Tasks Research Found information regarding geography, topography, culture and lifestyle of the Virgin Islands Found information regarding geography, topography, culture and lifestyle of the Virgin Islands Also on rainwater management, erosion control methods, water flow, and cost estimates of materials used for our solution. Also on rainwater management, erosion control methods, water flow, and cost estimates of materials used for our solution.

11. Communication Partner Organization – Julie Wright, Dale Morton Partner Organization – Julie Wright, Dale Morton Local Engineer – Jerry Runyon Local Engineer – Jerry Runyon Colorado State University – Lee Macdonald, Carlos Ramos Colorado State University – Lee Macdonald, Carlos Ramos

12. Issues Change of personnel Change of personnel Phone vs. Email Phone vs. Email Differing opinions: Differing opinions: what is the problem? what is the problem? what portion should we tackle? what portion should we tackle? who are we doing the project for? who are we doing the project for?

13. Problem Definition Need to reduce erosion Need to reduce erosion Source 1: Unpaved roads Source 1: Unpaved roads Source 2: Improperly Developed homesites Source 2: Improperly Developed homesites We chose: Driveways coming off homesites leading to unpaved roads We chose: Driveways coming off homesites leading to unpaved roads

14. Design Process Identify Problem Identify Problem Research Research Elimination (Rd. 1) Elimination (Rd. 1) Evaluation of survivors Evaluation of survivors Elimination (Rd. 2) Elimination (Rd. 2) Design Design

15. Identify Problem Identify Problem We have this erosion problem. We have this erosion problem. + We have only one semester._ + We have only one semester._ = Must narrow scope. = Must narrow scope. Contacts and Partner Org. seems to think the roads are the biggest culprits. Contacts and Partner Org. seems to think the roads are the biggest culprits. …We shall focus on individual homesite driveways! …We shall focus on individual homesite driveways!

16. Design Research Gather as much info on Best Management Practices (BMPs) as was relevant and available. Gather as much info on Best Management Practices (BMPs) as was relevant and available. Want BMPs pertaining to specific functions: Want BMPs pertaining to specific functions: reduction of runoff volume reduction of runoff volume reduction of runoff velocity reduction of runoff velocity retention of runoff retention of runoff

17. Elimination (Round 1) ding ding Used the following general criteria to select 3 BMPs to do further investigation: Used the following general criteria to select 3 BMPs to do further investigation: 1.) must be effective in reducing stormwater runoff volume and velocity during big rainstorms; 2.) must be easy to implement on already existing homesites; 3.) requires low maintenance; 4.) should be durable; 5.) must be cost efficient.

18. Evaluation of 3 BMPs Raingardens – not very compatible w/ topography, maintenance troubles, costly Raingardens – not very compatible w/ topography, maintenance troubles, costly Swale/Dike – not very compatible w/ topography, lacks durability Swale/Dike – not very compatible w/ topography, lacks durability Waterbar – works on steep slopes, can handle large water flows, low cost, low maintenance, quite durable, and can be installed relatively easily…Eureka Waterbar – works on steep slopes, can handle large water flows, low cost, low maintenance, quite durable, and can be installed relatively easily…Eureka

19. Elimination Waterbar it is!

20. Waterbar Design Waterbar alone will not be sufficient But a waterbar-basin combo will be quite effective But a waterbar-basin combo will be quite effective A concrete basin or an earthen basin lined with impervious material works, as a good % of home owners would like to reuse water to irrigate plants on their property A concrete basin or an earthen basin lined with impervious material works, as a good % of home owners would like to reuse water to irrigate plants on their property

21. Design Calculations Runoff volume for driveway using NRCS Curve Number method Runoff volume for driveway using NRCS Curve Number method Velocity of flow using Manning’s equation Velocity of flow using Manning’s equation

22. Evaluation of Design Effectiveness Find erosion reduction potential from installation of design on individual homesite Find erosion reduction potential from installation of design on individual homesite Find overall reduction from the number of participating homesites Find overall reduction from the number of participating homesites

23. Stream Power Equation which gives the power of a fluid running off of a surface Equation which gives the power of a fluid running off of a surface Power of fluid is directly related to its potential to cause erosion Power of fluid is directly related to its potential to cause erosion Ω = ρ * g * S * Q (N/s) (Bagnold, 1966)

24. Construction and Testing of Waterbar Used conveyor belt material, angle iron, and hardware Used conveyor belt material, angle iron, and hardware Resistance to traffic and flow diversion effectiveness Resistance to traffic and flow diversion effectiveness

30. Preliminary Cost Estimation Waterbar materials = $15/bar Waterbar materials = $15/bar Catch Basin = > $1000 for smallest event Catch Basin = > $1000 for smallest event Labor = ?? Labor = ?? Needs to be investigated further in future semesters Needs to be investigated further in future semesters

31. Progress so far Solution: waterbar used to divert the water off the bottom of the driveway and into a holding basin. Solution: waterbar used to divert the water off the bottom of the driveway and into a holding basin. Spreadsheet requiring inputs from each site to determine the size of the collection basin. Spreadsheet requiring inputs from each site to determine the size of the collection basin. Calculated effectiveness of the waterbar in reducing flow. Calculated effectiveness of the waterbar in reducing flow.

32. Semester Deliverables Waterbar solution for runoff diversion Waterbar solution for runoff diversion Initial waterbar design and prototype Initial waterbar design and prototype Spreadsheet program for basin size estimation and flow velocity Spreadsheet program for basin size estimation and flow velocity

33. Plans for the Future Design acceptable retention basin Design acceptable retention basin Tailor waterbar design to specific test site Tailor waterbar design to specific test site Eventually implement design on test Eventually implement design on test site in VI Actually measure reduction in flow Actually measure reduction in flow and erosion reduction Come up with a final cost analysis Come up with a final cost analysis