Developing restoration strategies for channelized headwater streams within a central Ohio watershed

Channelized headwater streams are a common landscape feature in the midwestern United States.  These streams have been channelized and maintained for removal of excess water from agricultural fields without regard for the aquatic biota.  Development of restoration strategies for channelized headwater streams in Ohio is limited by the lack of comparative habitat and biological information from unchannelized headwater streams.  The Upper Big Walnut Creek is a 492 km² watershed in central Ohio that has been identified as a priority impaired watershed.  We sampled geomorphology, riparian vegetation, hydrology, water chemistry, and fishes in two channelized and two unchannelized headwater streams in this watershed from January 2005 to December 2006.  We compared abiotic and biotic characteristics of channelized and unchannelized streams to identify potential restoration strategies.  Channelized streams contained greater cross-section area and top bank width than unchannelized streams.  Unchannelized streams had a greater density of woody vegetation and woody to herbaceous vegetation ratio than channelized streams.  Unchannelized streams had greater water velocity and wet width during baseflow conditions than channelized streams.  Loadings of total nitrogen, total phosphorus, and simazine were greater in channelized than unchannelized streams.  Channelized streams had a greater percentage minnows (Cyprinidae) and less percentage darters (Percidae) than unchannelized streams.  Our results assisted with developing a range of potential restoration strategies for channelized headwater streams in the Upper Big Walnut Creek watershed.  Additionally, our use of unchannelized headwater streams as a guiding image identified potential goals typically not considered when designing restoration strategies.