Agenda Date: 10/15/2019
Subject:
Title
Resolution 50-2019: Approving an Intergovernmental Agreement with Mile High Flood District for construction of drainage improvements for Lee Gulch at Broadway
Body
|
Prepared by: |
Carolyn Roan, Water Resource Manager |
PURPOSE:
To approve an Intergovernmental Agreement (IGA) with Mile High Flood District for funding construction of a headwall, wing walls, and channel stabilization at the Lee Gulch culvert under Broadway.
PRESENTATIONS:
Staff Presenter(s): N/A
Additional Presenter(s): N/A
SUMMARY:
The 66-inch diameter metal culvert for Lee Gulch under Broadway experienced partial collapse in 2015. An emergency repair ensured stabilization of the roadway, which included a lining of the inside of the existing culvert. At the time, the emergency repair used nearly all of the available funds in the Storm Drainage Enterprise fund, and headwalls and wing walls on the culvert were delayed. The staff has worked with an engineer to design the project. These measures will limit further erosion around the culvert entrance, which threatens the steep roadway embankment of Broadway. The downstream side of the culvert is not experiencing erosion of concern. Staff collaborated with Mile High Flood District to assist in the cost of construction. Mile High Flood District does not typically assist in construction funding for headwalls and wing walls that are intended for stabilization of roadway embankments, but have agreed to fund the grouted boulders needed in the bottom and sides of the Lee Gulch channel.
PRIOR ACTIONS OR DISCUSSIONS:
This subject has not previously been discussed with council.
ANALYSIS:
Staff Analysis
Staff has been concerned about the erosion occurring at the entrance of the culvert since the emergency repair. This erosion threatens the roadway embankment because the embankment is very steep, and as such, any erosion at the toe of the embankment slope risks loss of significant amounts of soil that can erode back into the roadway and sidewalk area. This would be of particular concern if Lee Gulch was to experience a significant flood event.
Council Goal, Objective, and/or Guiding Principle
By leveraging funds from Mile High Flood District, this meets Goal 2 of the Council; Financial Sustainability/ Objective 5 to identify opportunities for funding capital needs. In addition, by utilizing one of Mile High Flood District’s pre-qualified contractors, it saves the city money and time associated with producing public bid documents and managing construction, and ensures a quality construction project by a qualified contractor.
Fiscal Impacts
This project will require $197,303 from the Stormwater Utility Fund and is currently proposed in the 2020 Budget and the 5-year fiscally constrained plan for the utility. The Mile High Flood District has agreed to provide $77,000 in cost sharing.
Alternatives
Should this agreement not be approved, the city will not have funding for construction of this project in the next year, and risk to the Broadway roadway embankment will continue. The city risks losing the cost share from Mile High Flood District.
STAFF RECOMMENDATION:
Staff recommends approval of this IGA for construction of drainage and stabilization improvements for Lee Gulch at Broadway.
PROPOSED MOTION:
Proposed Motion
I move to approve the resolution approving an Intergovernmental Agreement with Mile High Flood District for construction of drainage improvements for Lee Gulch at Broadway.