Beaver Creek Bank Stabilization

Project Name

Beaver Creek Bank Stabilization Adjacent to the Augustine Subdivision

Preliminary Construction Plan
Click to view the plans (PDF)

Project Map
Click to view (PDF)

Estimated Cost
$420,000 covering engineering and construction

Project Update
On December 4, 2017, the Johnston City Council awarded the construction contract for the project to TK Concrete, Inc. from Pella, Iowa. TK Concrete will be responsible for completing the project. Construction is anticipated to begin the mid-January, with a targeted completion date of June 30, 2018.

The following is an update as of January 18, 2018:
The contractor TK Concrete intends to get started next week with tree removal for the haul route and staging area, which they estimate will take at least a week, this will be an area from NW 86th Street down to Beaver Creek. Most of the trees designated for removal are dead or are small stature ash trees. A pink ribbon was placed along NW 86th street for where the haul route will begin. TK plans to close the trail along NW 86th Street during hauling operations.

Foth’s survey team will plan to be out next Wednesday (1/24) to stake and mark in the creek where riprap should go. TK plans to begin construction immediately following survey.

Duration of construction is unknown at this time, but they will begin at the far south end of the project and work their way back to the north end.

The contractor intends to complete the bulk of construction activities from Beaver Creek and all equipment, materials and machinery will be located/used in the area of Beaver Creek and not along the creek banks adjacent to the residential properties.

Construction access to the project will be provided via a temporary access route that will be installed from NW 86th Street located just south of NW 70th Avenue.

To ensure the construction occurs within the designed parameters, the City has contracted Foth to provide a Construction Inspector who will be onsite monitoring construction activity. Katie Goff is the Construction Inspector who will be onsite, should you have questions or concerns during construction she can be reached at 515-251-2529.

This activity will require increased truck traffic and intermittent lane and sidewalk closures along NW 86th Street. Please use caution as you are traveling through this area.


Design Engineering: February – December 2017
Project Bidding: December 2017
Construction: January to June 2018


Joshua C. DeBower, P.E.
Foth Infrastructure & Environment, LLC
8191 Birchwood Court, Suite L
Johnston, IA 50131
Email Joshua DeBower

City Staff Project Contact
David Wilwerding, AICP
Community Development Director
City of Johnston
Email David Wilwerding

Project Description
In 2010 the City of Johnston completed a Watershed Assessment and Stormwater Management and Action Plan for the entire community. This plan identified 10 priority projects that were needed to address erosion, protect public and private property and improve water quality. One of these projects identified was the Beaver Creek Bank Stabilization adjacent to the Augustine subdivision. Severe bank erosion exists along the northern edge of the Augustine subdivision on the west bank of Beaver Creek. The height of the bank is over 20 feet and this area has seen active erosion since the flooding of 2008.

The project involves the armament of an existing storm sewer outlet to correct erosion and the installation of a Longitudinal Peak Stone Tow Protection (LPSTP) with stone tie backs. This method has already been used in another area along Beaver Creek successfully and is intended to stabilize the banks at the normal flow elevations and allows for the banks to rebuild themselves over time as the area behind the LPSTP will fill with silt deposited during high water events. This method avoids the need to use excessive amount of rip rap armament up the entire embankment.

Project Funding

The Beaver Creek Bank Stabilization project is funded by the Johnston Stormwater Utility, which was implemented in July 2012 to create a dedicated funding source for projects that reduce erosion, protect properties and infrastructure from flooding and to improve water quality within the City of Johnston. For more information on the stormwater utility, visit the stormwater projects page.