Groundwater Flow Problems in Colorado Springs

1. Groundwater Flow Problems in Colorado Springs (… or, it’s why they call it “the Springs”) 1

2. Presentation Outline • Background on Groundwater Underdrains • Problems – Underdrain System Failures • Proposed Solution • Underdrains vs. Sump Pumps? • Implications of Proposed Solution • Conclusion & Recommendations

3. Groundwater Underdrains – Technical Team City EngrHBACSU Cam McNair Bobby Ingels Brent Schubloom Steve Kuehster Bob Branson Charlie Morgan Brian Huth Marla Novak Mike Weber Tom Repp Marc Whorton Peter Bond 3

4. 4 Groundwater Conveyance • Groundwater can be conveyed through an underground pipe network called an “Underdrain” system. • Protects foundations and basements from flooding. • Used in Colorado Springs since the 1960’s – 1970’s.

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6. 6 Background – What are Underdrains? SANITARY SEWER UNDERDRAIN

7. Underdrain failures can cause public health problems No claims to Ownership Liability to Fund Repairs Inadequate Standards for installation No Maintenance 7 What are the issues?

8. 8 Recent Underdrain Failures • 6400 block, Summer Grace Street • 1300 block, West Costilla Street • Phil Long Expo Center • 2500 block, Integrity Court • 6800 block, Grand Prairie Drive • etc. • Costs to repair average $10K - $50K each

9. 9 Underdrain Failures STORMWATER OUTFALL INTO SAND CREEK PLUGGED UNDERDRAIN MAIN SUMP PIT OUTFALLS SANITARY MAIN CRAWL SPACE BASEMENT CRAWL SPACE

10. Proposal = Partnership among HBA, CSU and City Engineering 10 What are the Solutions?

11. 11 Proposal • City Takes Ownership of Underdrain Main lines serving single-family residential homes and nonresidential that opt in to connect to public UD mains • HBA - As representatives of the building industry, has agreed that developers & builders are willing to pay reasonable fees/costs for a long term solution to the UD problem. • CSU - reviews designs, inspects installations, and makes repairs when necessary • SWENT - manages funds, maps systems, coordinates CSU repairs, coordinates with State (CDPHE)

12. 12 What would the City Own?

13. 13 What would the City Own?

14. What will it cost?ALL ARE ONE TIME FEES Developer- CSU plan review and inspection fee= $23 per SF Residential lot (≤ triplex). $92 per Non-Residential lot (with GU main). CCTV inspections on T&M basis. Builder - City Underdrain maintenance fee= $60 per SF building permit. Non-Residential plus the mandatory State permit: (if connected) < 2 acres $ 60 2-5 acres $120 5-10 acres $180 > 10 acres $300 14

15. 15 What about basement/crawlspace Sump Pumps?

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17. 17 Sump Pumps • Ground water volumes can be so over-whelming such that a pump cannot keep up with the groundwater infiltration • Resulting in flooding

18. Sump Pumps 18 • Groundwater Underdrain fees are intended to be used to repair and maintain Underdrain systems only. • Not for sump pumps or discharges from sump pumps. • Groundwater Underdrains cannot be retrofitted in areas that were not originally built with them – cost prohibitive. • City Street Division uses “French Drains” (shallower collection systems) for sump pump discharge problems.

19. 19 Implications with Implementing the Proposal • Financial • Liability/Risk • Null Alternative

20. 20 Conclusions & Recommendations City/CSU/HBA – PARTNERSHIP RECOMMENDS: • City Takes Ownership • DEVELOPERS and BUILDERS agree to pay reasonable fees to CSU and City (SWENT) • SWENT manages the money and the overall program • CSU performs duties of plan reviewer, inspector, and repair contractor

21. 21 For More Information: • Details available on web - • Technical Standards • City Code Changes • Fees • Rate Case www.SpringsGov.com/ GroundwaterUnderdrains

22. 22 Questions