Water Quality in Perimeter Canal of the Loxahatchee National Wildlife Refuge in South Florida.

The ARM Loxahatchee National Wildlife Refuge (Refuge) is an area designated to maintain water storage and flood control; and is part of the remnant Everglades ecosystem in south Florida. Storm water runoff from agriculture and urban areas has been historically discharged into the L40 canal surrounding the refuge. High phosphorus (P) sediments have accumulated in the L40 canal which can be easily transported downstream. Storm treatment Area (STA-1E) has been discharging low P water to the L40 canal at different flow rates since 2004. The L40 canal was monitored for three water years for the water quality changes with respect to various P forms, and total suspended solids (TSS). L40 canal had had higher P concentrations during wet seasons than dry seasons. Individual water sampling surveys under drainage flow conditions showed high variability, with the higher concentrations measured at the beginning of rainfall season. Both total P and particulate P concentrations were significantly correlated (p<0.05) with TSS concentrations during flow and no-flow drainage conditions. Three water year data (May 2006-April 2009) reflected that L40 Canal water quality is a function of both intensity and frequency of storm water treatment discharges from the constructed wetland systems.