For over 10 years, the Foundation supported programs and projects to improve Great Lakes water quality and reduce untreated combined sewer overflows, which pollute the region’s rivers and lakes. In total, the Foundation’s support for combined sewer overflow reduction efforts amounted to more than $20 million over the last decade.
The Foundation recently commissioned a study to better understand the remaining sources and volumes of untreated combined sewer overflows in the region and future opportunities and priorities for continued combined sewer overflow reduction. The Foundation retained GEI Consultants to complete the study and worked closely with an Advisory Group facilitated by Public Sector Consultants. It included representatives from the Great Lakes Water Authority, Detroit Water & Sewerage Department, Southeast Michigan Council of Governments, Macomb County Public Works, Oakland County Water Resources, and Wayne County Drain Commissioners office.
The completed study notes several measurable successes on combined sewer overflow reduction in the region to date. More than $2 billion was invested. Nine new facilities, collectively treating 97% of wet weather events, were built, and the number of uncontrolled combined sewer overflows in the region declined from 310 to 76. Moving forward, regional stakeholders will continue working collaboratively to address the remaining 3% (approximately 3.5 billion gallons in 2020) of untreated combined sewer overflows. This will require an estimated capital investment of $2.29 billion, not considering long-term operation and maintenance costs and the impacts of climate change. The summer of 2021 set record events for precipitation in Southeast Michigan. During a June event, many rain gauges measured more than a 100-year event and three gauges registered a 1,000-year event. This contributed to flooded freeways, basement backups, and damage to businesses.
After pausing our grantmaking to complete a study of the combined sewer overflow challenge, the Foundation is exploring next steps to restart its grantmaking to address this threat to Great Lakes water quality. We will share those next steps this spring.