Promenade Improvement Project Complete
The City of Sioux City would like to announce the completion of the Promenade Improvement Project. Enhancements to downtown Sioux City, including the addition of greenspace, are a priority of the City Council. The Promenade Improvement Project accomplished several goals including improved stormwater drainage, improved water quality through the addition of green infrastructure, and providing increased access to green space in our downtown area.
This project was the result of a collaborative effort between the City of Sioux City and staff with the Iowa Department of Agriculture and Land Stewardship, with grant assistance provided by the Iowa Department of Agriculture and Land Stewardship Water Quality Initiative Program. The City was awarded a grant in the amount of $80,000 for use on the construction of a water quality improvement project. The project was designed by ISG Consulting Group, and constructed by MLS Landscape & Design.
Impervious area is any type of ground cover that does not allow for stormwater infiltration; examples include asphalt, concrete, and the pavers that previously existed at the Promenade. Impervious area increases the volume of stormwater runoff from those areas and can contribute to streambank erosion problems, often carrying with it any existing nutrients and pollutants that drain directly to our waterways and have a negative effect on water quality. Low Impact Development (LID) features or “Green Infrastructure” such as rain gardens, permeable pavers, bioretention cells, tree trenches, planting native plants, and soil quality restoration, work to improve water quality by decreasing or eliminating stormwater runoff. The features implemented as part of this project - bioretention cells, tree trenches, and soil quality restoration - will work to capture, infiltrate, and filter stormwater runoff from the Promenade plaza and a portion of 4th and Virginia Streets. Those who visit the site during a rain event will observe the vegetated areas filling up with stormwater and during large rain events may see stormwater overflowing out of intake structures located in the bioretention cells; these features were designed to function in this manner to provide maximum water quality benefits.
Educational signs are currently being designed and will feature a profile view of the bioretention areas that will provide an explanation of their function and a list of native plants that have been used throughout the project.