Groundwater Flow Problems in Colorado Springs

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Groundwater Flow Problems in Colorado Springs
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• ( or, its why they call it the Springs)

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Presentation Outline

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

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Groundwater Underdrains Technical Team
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• City Engr HBA CSU
• Cam McNair Bobby Ingels Brent Schubloom
• Steve Kuehster Bob Branson Charlie Morgan
• Brian Huth Marla Novak Mike Weber
• Tom Repp Marc Whorton Peter Bond

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Groundwater Conveyance
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• 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 1960s
  1970s.

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Background What are Underdrains?
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SANITARY SEWER
UNDERDRAIN
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What are the issues?
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• Underdrain failures can cause public health
  problems
• No claims to Ownership
• Liability to Fund Repairs
• Inadequate Standards for installation
• No Maintenance

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Recent Underdrain Failures
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• 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

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Underdrain Failures
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STORMWATER OUTFALL INTO SAND CREEK
PLUGGED UNDERDRAIN MAIN
SUMP PIT OUTFALLS
SANITARY MAIN
CRAWL SPACE
BASEMENT
CRAWL SPACE
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What are the Solutions?
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• Proposal Partnership among HBA, CSU and City
  Engineering

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Proposal
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• 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)

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What would the City Own?
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What would the City Own?
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What will it cost?ALL ARE ONE TIME FEES
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• Developer- CSU plan review and inspection fee
• 23 per SF Residential lot ( triplex).
• 92 per Non-Residential lot (with GU main).
• CCTV inspections on TM basis.
• Builder - City Underdrain maintenance fee
• 60 per SF building permit.
• Non-Residential plus the mandatory State permit
• (if connected) lt 2 acres 60
• 2-5 acres 120
• 5-10 acres 180
• gt 10 acres 300

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What about basement/crawlspace Sump Pumps?
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Sump Pumps
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• Ground water volumes can be so over-whelming such
  that a pump cannot keep up with the groundwater
  infiltration
• Resulting in flooding

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Sump Pumps
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• 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.

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

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Conclusions Recommendations
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• 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

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

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Questions
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