Abstract

Weather and management practices were monitored to assess the impact on water quality at four stormwater retention ponds used for irrigation. Two retention ponds were located at Bayville Golf Club (BGC) in Virginia Beach, VA, and two were located at Knotts Creek Nursery (KCN) in Suffolk, VA. Total dissolved N concentrations were examined at increasing depths and over time at the pond inflows and middles. Multiple fertilizer products with variable analyses were applied more frequently at BGC, but N concentrations were consistently higher at KCN. In 2002, a drought year, water temperatures fluctuated little over the season or with depth, regardless of location. N concentration ranges were 1.0—3.5 mg·liter⁻¹ (ppm) at BGC and 2.5—6.0 at KCN. Nitrogen concentrations fluctuated as water depth increased. In 2003 rainfall was above average. Water temperatures fluctuated more over the season than in 2002 and with increasing depth. N concentration ranges were 0.75—4.2 mg·liter⁻¹ (ppm) at BGC and 0.5—6.0 at KCN; and were consistent as water depth increased. Both water temperatures and N concentrations fluctuated dramatically at the inflow locations compared to the middles of the ponds.