City of Cedar Falls Improving Water Quality with Permeable Pavement

Protecting water quality has been a priority for the City of Cedar Falls for years. This has included implementing several streambank stabilization projects as well as installing over 50 bioretention cells throughout the City.  Over the last few years, a new initiative has taken shape.  In reviewing the cost of maintaining the many gravel alleyways the City identified an opportunity to manage stormwater and reduce ongoing expenses.  A City-wide assessment was undertaken to look at the alleys for slope, drainage area, and proximity to storm drains.  Based on this information, the City prioritized high-needs alleys and set a plan to upgrade these alleys with permeable pavement.    In 2015, the City of Cedar Falls was awarded funds through the Water Quality Initiative Urban Projects grant to implement permeable pavement on two alleys.  These dollars were then matched with additional funds from the DNR Section 319 Program through the Dry Run Creek Watershed Improvement Project.  This alley project included implementing 6,000 square feet of permeable pavement which would manage almost 3 acres of land.  Together these practices are treating over 660,000 gallons of stormwater, reducing 1,800 pounds of sediment, seven pounds of nitrogen, and two pounds of phosphorus each year.

The response to this project was largely positive.  So much so, that the City has continued to implement permeable paver alleys, even without financial assistance from any grants over the last two years.  This has included an additional four permeable alleys completed with another alley on the horizon and plans to continue this program in the coming years.  The four completed alleys have comprised an additional 8,700 square feet of pavers draining 2.25 acres, and infiltrating over 725,000 gallons of stormwater runoff.  Two of these alleys implementing an innovative design with a narrow strip of pavers down the center while maintaining the large underground rock base.  This helped to slightly reduce the price tag for installation as well as ongoing maintenance cost.

These permeable paver alleys are also helping to improve the aesthetics of Cedar Falls and citizens are taking note.  These alleys have been instrumental in raising awareness for water quality, stormwater management, and the Dry Run Creek Watershed Improvement Project.  It has even inspired some residents to implement permeable pavement on their own properties and convert their concrete driveways to an infiltration-based practice.  Improving water quality takes investment from all members of the community.  With Cedar Falls’ continued leadership, urban conservation efforts are making a more sustainable city to live and grow.