Agenda Date: 04/01/2025
Subject:
Title
Resolution 16-2025: Approving an Intergovernmental Agreement with Mile High Flood District for design and construction of drainage and flood control improvements for Little’s Creek from Caley Avenue to Gallup Street
Body
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From: |
James L. Becklenberg, City Manager |
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Prepared by: |
Brent Soderlin, Director of Public Works & Utilities |
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Sarah White, Water Resources Manager |
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Presentations: |
N/A |
PURPOSE:
Approval of an IGA with Mile High Flood District (MHFD) for design and construction of drainage and flood control improvements for Little’s Creek from Caley Avenue to Gallup Street.
LONG-TERM OUTCOME(S) SERVED:
Safe Community; High-Quality Governance; Sustainable Community with Natural Beauty
DISCUSSION:
Little’s Creek drainageway extends from East Dry Creek Road in Centennial to its outfall at the South Platte River. This regional drainageway is regulated by the Federal Emergency Management Agency (FEMA). Much of the residential development along Little’s Creek pre-dated the determination of the creek’s floodplain limits and the understanding of impacts of drainage basin development that exists today. Little’s Creek was left as a small “ditch” along Sterne Parkway as the surrounding neighborhoods were built, with small culverts at the various roadway crossings of the creek. As a result, there had been frequent flooding of the channel and at roadways, as the drainage basin developed. As this problem was identified, the city partnered with MHFD on projects to retrofit the channel and culverts, as budget allows, to lessen the extent and frequency of flooding on roads and adjacent properties as much as possible. As a result, future more frequent flood events will be better controlled. However, larger storm events may still flood roads and some properties.
The proposed improvements for the Little’s Creek reach between S Gallup Street and W Caley Avenue will provide bank stabilization throughout the channel reach, improved channel capacity, replacement of a pedestrian bridge, realignment the sanitary sewer adjacent to the creek, and improvement the corridor trail. This IGA would authorize funding to complete the design of the project. Future amendments to this agreement are anticipated to fund construction of the project. Pending funding availability, the project is anticipated to be constructed in 2026.
BACKGROUND:
The master planning document “Major Drainageway Planning: Lee Gulch Little Creek” dated September 1978 identified several reaches of Little’s Creek that required improvements. The City of Littleton, in partnership with MHFD, completed recommended improvements at the Little’s Creek crossing at Gallup Street in 2021. That project was completed to increase the flood capacity of the channel as much as possible and improve local street drainage. This project at Gallup Street keeps floodwaters under the roadway for events up to an approximately 5-year (20% annual chance) flood and lessened the depth and frequency of roadway overtopping in larger floods. This increases safety for the traveling public and adjacent properties and lessens damages during floods.
The city and MHFD then completed a Conceptual Design Report, dated August 2022, to evaluate potential channel improvements at Little’s Creek between Caley Avenue and Gallup Street to address worsening channel erosion concerns and evaluate potential for flood capacity improvements. This project study reach is bounded by Gallup Street downstream to West Caley Avenue, adjacent to residential development, Little Raven Elementary School and Littleton Baptist Church.
The project design has been funded by MHFD maintenance funds. The project is now nearing 100% design and requires additional FEMA documentation due to work within the 100-year floodplain. There is also some outstanding documentation from the Little’s Creek at Gallup project that will be incorporated into the final FEMA updates.
The Little’s Creek Caley to Gallup Project proposes bank stabilization throughout the channel reach, improving channel capacity, replacing a pedestrian bridge, realigning the sanitary sewer adjacent to the creek, and improve the corridor trail.
Prior Actions or Discussions
This project has not been previously discussed with council.
FISCAL IMPACTS:
Approval of this IGA authorizes not more than $70,000 be contributed by the city for final design of the project. The city will be responsible for a minimum contribution of 50% of the project costs, with MHFD also contributing approximately 50% of the project cost. The total project cost is not finalized, and it is anticipated that funds for construction will be added to this agreement through future amendments. Staff will continue to search for additional funding sources as final design continues. This $70,000 contribution will be funded from the 2025 Storm Drainage Enterprise Fund budget.
STAFF RECOMMENDATION:
Staff recommends approval of the resolution.
ALTERNATIVES:
If not approved, the city would need to fund the project without the contribution from MHFD, and the project would be delayed until sufficient funds can be identified within the Storm Drainage Enterprise Fund.
PROPOSED MOTION:
Proposed Motion
I move to approve Resolution 16-2025 approving an Intergovernmental Agreement with Mile High Flood District for design and construction of drainage and flood control improvements for Little’s Creek from Caley Avenue to Gallup Street.