Water Quality Changes from Riparian Buffer Restoration in Connecticut

One‐half of a 35‐ by 250‐m riparian buffer cropped in corn ( Zea mays L.) was seeded with fine leaf fescue ( Festuca spp.) and allowed to remain idle to determine water quality changes resulting from riparian buffer restoration. A corn control was also used in this paired watershed design located in Connecticut. Water, N, and P fluxes were determined for precipitation, overland flow, and ground water. Also, an N mass balance was calculated. Total Kjeldahl nitrogen (TKN) and total phosphorus (TP) concentrations significantly ( P < 0.05) increased as ground water flowed through the restored buffer. Nitrate N (NO 3 ‐N) concentrations declined significantly but most (52%) of the decrease occurred within a 2.5‐m wetland adjacent to the stream. An N mass balance for the 2.5‐m strip indicated that denitrification only accounted for 1% of the N losses and plant uptake was from 7 to 13% of the N losses annually. Ground water was the dominant source of N to the buffer and also the dominant loss. Restoration of the riparian buffer decreased ( p < 0.05) overland flow concentrations of TKN by 70%, NO 3 ‐N by 83%, TP by 73%, and total suspended solids (TSS) by 92% as compared with the control. Restoration reduced ( p < 0.05) NO 3 ‐N concentrations in ground water by 35% as compared with the control. Underestimated denitrification and dilution by upwelling ground water in the wetland area adjacent to the stream were believed to be primarily responsible for the decreasing NO 3 ‐N concentrations observed.