Project Overview
Hall Creek runs from just north of the city to the 55-acre Ballinger Park, draining into Lake Ballinger. Ballinger Park was allowed to return to a more natural condition starting in 2012, when the old golf course was decommissioned. The city’s future vision for the park is encapsulated in the Ballinger Park Master Plan, approved by the City Council in 2015.
The plan includes a substantial ecological restoration component for the portion of Hall Creek that runs through Ballinger Park, together with the park ponds and wetland areas in the park. The environmental restoration portion of the plan was estimated in 2015 to cost $5 million. In order to fulfill this component of the Ballinger Park Master Plan in a cost-effective manner, the city approached the Corps of Engineers as a project partner. In the summer of 2018, the Corps determined that the project met federal interests by improving the quality of the environment and having a positive impact on significant ecosystem resources. A project team consisting of Corps and city staff was brought together at that time to develop a scope of work and costs for the feasibility study for the project.
The goal of the restoration project is to address current constraints on ecological health in Ballinger Park, including increased channelization of Hall Creek and loss of connection between the creek and its floodplain. There is a lack of velocity refuge for fish and other stream biota. Invasive plants, including blackberry and nightshade, are dominant around the streams and wetland areas.
The project would create habitat in an already urbanized and rapidly-developing urban area, particularly for species of concern such as amphibians, and would also provide significant habitat for migrating birds.
Alternative plan development and evaluation was required during the feasibility phase to determine the most optimal channel, wetland, and riparian restoration measures to improve habitat conditions. Public input was also considered in the development of the selected design. The approved design, shown to the right, will include:
- Removal of old, non-functional tennis court – replaced with green space
- Creek floodplain reconnection
- Creek channel diversification for habitat
- Removal of bank armor
- Bank restoration
- Invasive plant removal, addition of native plants
- Protection of habitat areas
- New creek channel: slows flow, creates refuge and rearing areas
- New pedestrian bridge
- Flyover boardwalk, which provides access and protects sensitive areas
- Protection of sight lines for safety
- Educational signage, targeted to specific audiences
The project also serves to fulfill the desire for a more natural park area, intended for quiet contemplation, as requested by residents in the Ballinger Park Master Plan.
Project Timeline and Costs
Feasibility: 2019-2020
Final Feasibility Study
General site plan
Design/engineering: 2020-2021
Construction: 2023
Total Mountlake Terrace estimated cost: 35%
