High Line Canal Conservancy

Smart water planning helps transform a 71-mile former irrigation canal into urban green infrastructure that will improve water quality and wildlife habitat while enhancing the resilience of underserved communities.

Since 1883, Denver Water used the 71-mile High Line Canal to transport water to irrigators growing food for the young city of Denver. Today, the historical waterway provides much-loved greenspace and recreational opportunities. With reduced water flows, however, the Canal’s future was uncertain. After determining that it could be used for regional water quality benefits while still serving irrigation customers, the High Line Canal Conservancy (HLCC) and its partners at Denver Water, Mile High Flood District, and adjacent jurisdictions chose to transform the Canal into an inspiring model of urban green infrastructure and smart water planning.

Building on a framework developed by HLCC, Biohabitats helped the organization implement two Pisces Foundation grants to demonstrate the stacked benefits of green stormwater infrastructure. Biohabitats worked closely with a Technical Leadership Team of stakeholder representatives to determine the goals and key benefits to be evaluated. Canal-wide mapping and analysis was used to measure and calculate select benefits of transitioning the entire Canal to green stormwater infrastructure. Ground-truthing and concept development in three pilot locations were used to test stormwater scenarios. Unit cost information for project components was obtained from HLCC, existing engineering reports, national precedent analyses, and stakeholder input. GIS data was used to quantify resources along the Canal and in three stormwater pilot reaches.

By integrating the benefits of stormwater with habitat and health values, the scenarios illustrate the ecological and social benefits the Canal can bring to the region’s communities and waterways. The study also shows the costs of not transforming the Canal.

TAGS

• Analysis+Planning
• Assessment+Monitoring