If You Build It Will They Come – Promoting Sustainable Aquatic Habitat in an Urbanized Watershed

Abstract

Water quality is one component of healthy, sustainable aquatic habitat. Variations in the natural flow regime and hydraulic characteristics also provide/produce suitable habitat for many different species. Lack of hydraulic diversity along the South Platte River has resulted in loss of suitable aquatic habitat and biotic diversity throughout the greater Denver area. The Metro Wastewater Reclamation District (the District) and Camp Dresser & McKee Inc. (CDM) have designed habitat improvements in a pilot reach of Segment 15 of the South Platte River. The primary goal of these habitat improvements is to improve/enhance biological diversity in an urbanized watershed. The design incorporates various combinations of high depth and low velocity, areas of shallow depth and high velocity, and protective cover. Affects of these improvements will be monitored for a number of years, and habitat improvements will be designed for future reaches based on the success of these pilot improvements. KEYWORDS Habitat restoration, geomorphology, urban watershed, South Platte River PROBLEM STATEMENTUrbanization and resource development have altered the natural flow regime of the South Platte River, changing the hydrology (including magnitude, frequency, duration, timing, and the rate of change), and hydraulics through channelization, structural modifications, and floodplain development. The geomorphic and hydrologic changes to the South Platte River in the greater Denver metro area have resulted in reduced habitat (both aquatic and riparian), elimination of sensitive species, and opportunity for invasive species to out-compete native species. Predevelopment ecosystems may not be able to reestablish in an urbanized watershed, but we may be able to create a new, sustainable system that mimics the natural ecology including habitat diversity, and eventually biotic (both aquatic and terrestrial) diversity providing opportunities for reestablishment of native species.