Agenda Date: 04/16/2019
Subject:
Title
Resolution 22-2019: Authorizing an amendment to an agreement regarding final design and construction of drainage and flood control improvements for Little’s Creek at Gallup Street between the city and the Urban Drainage and Flood Control District (UDFCD)
Body
|
Presented By: |
Keith Reester, Public Works Director |
POLICY QUESTION:
Does city council support amending the Intergovernmental Agreement (IGA) with UDFCD for construction of improvements for Little’s Creek at Gallup Street?
BACKGROUND:
Little’s Creek flows through Littleton from Broadway to the South Platte River, along Sterne Parkway, Sterne Park, and through downtown.
The UDFCD and City of Littleton completed a flood hazard area delineation for Little’s Creek in 1977 and preliminary design report in 1978. Almost all improvements recommended by the design report have been completed in Littleton. At South Gallup Street, the report recommends a large culvert to replace the smaller culverts to reduce flooding of the roadway.
This location has typically experienced flooding of the roadway and adjacent properties once or more each year. Local residents have routinely contacted the city about this flooding. This project has been in planning for multiple years. Progress was delayed in 2016 due to the emergency repair of the collapsed culvert at Lee Gulch at Broadway. The Little’s Creek project remains a priority in the Storm Drainage Utility capital improvement plan. The original IGA included the culvert replacement and upstream stream stabilization through Angeline Little Greenway Park; however, the culvert has higher priority for construction. Conceptual design of upstream improvements is complete and may move forward as a future project.
The proposed box culvert at the intersection of South Gallup Street and West Peakview Avenue will limit the frequency of flooding on the roadway and surrounding properties, some of which are in the floodplain. The culvert will have capacity for a range of flood flows, but not the 100-year event, due to site constraints such as horizontal space and vertical limitations beneath the roadbed.
All other recommended improvements on Little’s Creek located within Littleton have been completed. The most recent improvements were on Sterne Parkway, between West Lake Avenue and South Windermere Street.
PRIOR ACTIONS OR DISCUSSIONS:
Council approved an IGA for this project in December 2015 to initiate the engineering design. It was anticipated that this would be a multi-year project.
This item was originally presented to Council on the Consent Agenda on April 2 and was removed by Council Member Cole for further discussion at the April 9, 2019 study session.
STAFF ANALYSIS:
The existing culvert on Little’s Creek at South Gallup Street is undersized and has very limited capacity for drainage. With a significant rainfall event, the stream frequently overtops the banks and the street floods. Proposed improvements call for a much larger culvert and channel transitions to convey stream flows. Additional storm sewer for local street drainage is anticipated to be constructed as part of this project. Extensive utility relocation, including water and gas mains, will also be needed. Staff has coordinated with utility companies such as Denver Water and Xcel Energy to undertake the necessary relocation in advance of the culvert project.
Preliminary design of the box culvert project is nearly complete under the existing IGA. This amendment of the agreement will provide some of the funding needed for construction. Another IGA amendment will likely be needed in 2020 to complete the total construction funding.
Construction is planned to begin in spring of 2020. UDFCD will continue to manage the project, with Littleton assistance.
OPTIONS/ALTERNATIVES:
If not approved, UDFCD may allocate these funds towards another local government project and there would be an insufficient amount of funding accumulated to begin construction in 2020.
FISCAL IMPACTS:
On large drainage and flood mitigation projects, the city partners with UDFCD. Neither agency has enough funding available within a single budget cycle to fully fund these large projects. Therefore, each agency appropriates 50% of the funding, held by UDFCD in a special fund, to pay for projects costs.
Under the original 2015 IGA, $500,000 was set aside (50% from each agency). To date, approximately $100,000 has been spent on preliminary design, surveying, environmental investigation, private property flood mitigation study, and other tasks. It is anticipated that another $100,000 will be needed to bring the project to final design, and $100,000 required for construction oversight. Construction costs are currently estimated at $1,000,000. This would bring the total project cost to $1,300,000.
UDFCD allocated another $250,000 for this project in 2019, which the city will match if the IGA amendment is approved. Littleton’s contribution will come from the Storm Drainage Enterprise Fund. In the 2019 budget, $250,000 has been allocated for this project. This is a multi-year project, and additional contributions from both the city and UDFCD will be required in 2020 to complete the construction.
UDFCD and Littleton contribution amounts and percentages from each party under this IGA amendment are proposed as follows:
|
|
Percentage Share |
Total Contribution |
|
UDFCD, 2015 |
|
$250,000 |
|
City of Littleton, 2015 |
|
$250,000 |
|
UDFCD, 2019 |
50% |
$250,000 |
|
City of Littleton, 2019 |
50% |
$250,000 |
|
TOTAL |
100.00% |
$1,000,000 |
STAFF RECOMMENDATION:
Staff recommends approval of the amendment to the IGA.
PROPOSED MOTION:
Proposed Motion
I move to approve the resolution authorizing an amendment to the Intergovernmental Agreement between the city and the Urban Drainage and Flood Control District regarding final design and construction of drainage and flood control improvements for Little’s Creek at Gallup Street.