A new study by Harvard Extension School has found that Prince George's County's Clean Water Partnership (CWP) has generated significant and lasting environmental, economic, and social benefits since its launch in 2015. Conducted as part of a graduate capstone project, the independent assessment concludes that the partnership has become a national model for delivering stormwater infrastructure through a long-term public-private partnership while creating measurable value for local communities. 

The CWP is a 30-year collaboration between Prince George's County, Maryland, and Corvias Infrastructure Solutions (CIS). The program was established to modernize the county's stormwater management system by planning, designing, constructing, financing, operating, and maintaining green infrastructure projects. Its primary objective is to reduce polluted stormwater runoff, improve local water quality, and help the county comply with its Municipal Separate Storm Sewer System (MS4) permit obligations and Chesapeake Bay restoration requirements. 

According to the study, the partnership has completed 428 stormwater improvement projects and restored nearly 5,000 acres of impervious surface. More than 300 green infrastructure installations, including bioretention systems, rain gardens, and other nature-based stormwater controls, have been implemented to capture and treat runoff before it reaches local waterways. These projects have strengthened environmental resilience while improving water quality throughout the county. Beyond environmental achievements, the research highlights the partnership's substantial economic and community impact. More than 77% of procurement spending, exceeding US$270 million, has been directed to minority-owned businesses and companies based in Prince George's County. Additionally, over 50% of total labor hours have been performed by county residents, supporting local employment and workforce development. The program's Mentor-Protégé initiative has also assisted 84 small businesses, enabling them to secure approximately US$60 million in competitive contract awards and build long-term business capacity. 

The Harvard Extension School study concludes that the CWP demonstrates how infrastructure investments can simultaneously deliver environmental restoration, regulatory compliance, economic development, and social inclusion. The researchers identify the partnership as a scalable model for other municipalities seeking to modernize stormwater infrastructure while promoting supplier diversity, local workforce participation, and long-term asset management. They also recommend expanding performance-tracking and business-development initiatives to maximize future community benefits.