Agenda Date: 10/21/2025
Subject:
Title
Resolution 92-2025: Approving the fourth amendment to the Intergovernmental Agreement with Mile High Flood District, regarding design and construction of drainage and flood control improvements for Lee Gulch at Broadway
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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Brent Thompson, City Engineer |
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Sarah White, Water Resources Manager |
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Presentations: |
N/A |
PURPOSE:
Approval of a fourth amendment the Intergovernmental Agreement between the City of Littleton and the Mile High Flood District regarding the design and construction of drainage and flood control improvements for Lee Gulch at Broadway.
LONG-TERM OUTCOME(S) SERVED:
Safe Community; Financial Sustainability; High-Quality Governance; Sustainable Community with Natural Beauty
DISCUSSION:
The City of Littleton, in partnership with Mile High Flood District (formerly Urban Drainage and Flood Control District) and Arapahoe County, studied the Lee Gulch and Little’s Creek drainageways in a master drainage study call “Major Drainageway Planning Lee Gulch Little Creek” in 1978. At the time of the study the basin was only 42% developed. The 1978 master study recommended additional culvert capacity and channel improvements at the Broadway crossing. The South Suburban Parks Master Plan further envisioned a linear park along the Gulch from the South Platte to County Line Road.
The 66” culvert carrying Lee Gulch under Broadway is a mixed material of reinforced concrete pipe (RCP) and corrugated metal pipe (CMP). The culvert was repaired in 2016 when a portion of the pipe collapsed. A geospray lining technique was used to provided structural reinforcement in addition to repairing the collapsed section. Unfortunately, the geospray has not held and the culvert is experiencing failures that require immediate repair.
Mile High Flood District (MHFD) provides a Capital Improvement Program in partnership with the local jurisdiction to provide design and construction of drainage and flood control infrastructure. The local jurisdiction must provide a minimum of 50% funding contribution. Capital funds are provided on a yearly basis from an available funding pool. MHFD has available capital and maintenance funds for the Lee Gulch at Broadway Project.
Due to the urgent nature of the Lee Gulch at Broadway Project, not all estimates or design components were complete at the time of the original IGA or amendments. All design is now complete and the final cost estimate of $13,515,021.62 has been provided by the contractor. All funding resources for the project have been secured and are outlined in the following Financial Impacts section. The IGA amendment, specific to this resolution presented to City Council, between the City of Littleton and MHFD capture the project funding contributions and agency roles during construction.
BACKGROUND:
In late 2024, the City of Littleton became aware of critical issues involving the culvert that conveys Lee Gulch under South Broadway. city staff, in partnership with MHFD, evaluated multiple design considerations, however it was determined the culvert repairs necessitate the full excavation of Broadway. Broadway also detains Lee Gulch floodwaters to the east and will overtop in large flood events. During concept design, city staff and design partners looked at alternative selections to alleviate the flood risk and identified the unique opportunity to install at 10-foot by 12-foot box culvert under South Broadway. Floodwalls will be installed to ensure the box culvert only conveys stormwater during large flood events (near 1% annual chance) and therefore can serve as a pedestrian underpass that would allow Lee Gulch Trail users to safely and efficiently cross under South Broadway to access the High Line Canal, Mary Carter Greenway Trails, and other area destinations. This rare opportunity to complete the underpass construction during the major roadway excavation for the culvert work presents several advantages including providing a safer crossing facility for trail users, cost sharing and savings between the two construction projects, as well as reduction in roadway impacts if the underpass was to be constructed separately as a future project. Additionally, completion of a trail crossing improvement of this significant scale and cost would not be feasible in the near-term without adequate funding resources.
In addition to the underpass, the project includes a 65-foot-long pedestrian bridge over Lee Gulch and associated trail amenities. The crossing, access, and trail improvements are supported by multiple City of Littleton and SSPRD plans that have identified the need to improve trail infrastructure and connectivity.
The culvert under Broadway at Lee Gulch needs immediate repair. Construction of a pedestrian underpass for the Lee Gulch Trail under Broadway will provide a long-envisioned safe crossing for trail users, providing access to multiple schools and parks, residential neighborhoods, commercial areas, and connections to the Mary Carter Greenway and High Line Canal Trail.
The culvert replacement work began in September 2025. All the work including the culvert replacement, construction of the underpass, and construction of the trail and bridge, is anticipated to be complete by October 2026. The City of Littleton, in coordination with MHFD is managing the construction of the culvert replacement work, underpass, trail, and pedestrian bridge.
Prior Actions or Discussions
An IGA with MHFD for the Lee Gulch at Broadway 2024 Project was approved by Council on September 17, 2024, per Resolution 102-2024.
IGA Amendment #1 with MHFD for the Lee Gulch at Broadway 2024 Project was approved by Council on December 3, 2024, per Resolution 121-2024.
IGA Amendment #2 with MHFD for the Lee Gulch at Broadway 2024 Project was approved by Council on March 18, 2025, per Resolution 20-2025.
IGA Amendment #3 with MHFD for the Lee Gulch at Broadway 2024 Project was approved by Council on May 6, 2025, per Resolution 49-2025.
FISCAL IMPACTS:
The current cost estimate for the entire project is $13,515,021.62. The culvert replacement portion of the project cost is being paid through a combination of City of Littleton Storm Drainage Enterprise Funds and MHFD funds. The pedestrian underpass and trail portion of the project cost is being paid through a combination of 3A Sales Tax Capital Improvement Fund, an Arapahoe County Open Space Grant, and contribution from South Suburban Parks and Recreation District.
MHFD is contributing an additional $1,130,000 as part of this IGA Amendment, along with $432,822.88 in internal transfers within funds currently held within MHFD’s escrow accounts.
Specific to this IGA with Mile High Flood District, the City’s expenditures will be from two city funding sources and internal transfers of previous city contributions to cooperative projects currently held within MHFD’s escrow accounts.
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Funding Source |
Expenditure Amount |
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Storm Drainage Enterprise Fund |
$1,030,000 |
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3A Sales Tax Capital Improvement Fund |
$2,200,000 |
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Internal Transfers |
$483,857.39 |
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Total |
$3,713,857.39 |
STAFF RECOMMENDATION:
Staff recommends approval of Amendment #4 to the Intergovernmental Agreement.
ALTERNATIVES:
If Council does not approve the IGA amendment, the construction of the culvert replacement and pedestrian underpass will likely not move forward without the Mile High Flood District’s resource contributions to the project. Leveraging funding from partners for projects such as this is critical to complete projects the city would unlikely be able to afford on its own.
PROPOSED MOTION:
Proposed Motion
I move to approve Resolution 92-2025 approving the fourth amendment to the Intergovernmental Agreement with Mile High Flood District, regarding design and construction of drainage and flood control improvements for Lee Gulch at Broadway.