HR: 11:15h
AN: NB32A-04    [Abstracts]
TI: Assessment of Stream Restoration Based on Measurements of Water Transit Time and Nutrient Retention.
AU: * Bukaveckas, P
EM: pabukaveckas@vcu.edu
AF: Virginia Commonwealth University, Department of Biology 1000 West Cary Street, Richmond, VA 23284 United States
AB: Injection experiments (Cl, N, P) were performed to quantify stream nutrient retention and related hydrodynamics (water transit time and transient storage) before and after restoration. A 1-km length of Wilson Creek (KY) was re-located from an incised and straightened channel along the margin of its former floodplain to a meandering constructed channel that followed remnant floodplain contours. Thirty experiments were conducted during a spring index period (2002-2003) in the channelized stream (pre-restoration), naturalized stream (post-restoration) and reference stream (Harts Run). Water velocity was higher and transient storage was lower through much of the naturalized (restored) segment relative to pre-restoration and reference stream conditions. Reductions in water transit time were a result of higher specific discharge (ratio of discharge to width) in the narrower, constructed channel. Despite faster water transit, nutrient retention was higher in the naturalized segment with values comparable to (P) or exceeding (N) those observed in the reference stream. Highest water and nutrient retention occurred in naturalized segments that were connected to the former channel. Retention was attributed to re-circulating zones that exchanged water between the active channel and the upstream backwater which was a remnant of the former channel.
DE: 0400 Biogeosciences
DE: 1860 Runoff and streamflow
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly