Water quality response to riparian restoration in an agricultural watershed in Vermont, USA

Achievement of management goals for Lake Champlain (Vermont/New York, USA a nd Quebec, Canada) will require reduction of agricultural phosphorus loads, the dominant nonpoint source in the Basin. Cost-effective phosphorus reduc tion strategies need reliable treatment techniques beyond basic cropland an d waste management practices. The Lake Champlain Basin Agricultural Watersh eds National Monitoring Program (NMP) Project evaluates the effectiveness o f livestock exclusion. streambank protection, and riparian restoration prac tices in reducing concentrations and loads of nutrients, sediment, and bact eria in surface waters. Treatment and control watersheds in northwestern Ve rmont have been monitored since 1994 according to a paired-watershed design . Monitoring consists of continuous stream discharge recording, flow-propor tional sampling for total P, total Kjeldahl N, and total suspended solids, grab sampling for indicator bacterial, and land use/agricultural monitoring . Strong statistical calibration between the control and treatment watershe ds has been achieved. Installation of riparian fencing, protected stream cr ossings, and streambank bioengineering was completed in 1997. Early post-tr eatment data suggest significant reduction in P concentrations and loads an d in bacteria counts in the treated watershed. Monitoring is scheduled to c ontinue through 2000.