2nd UF Water Institute Symposium Abstract

Submitter's Name Alphonce Guzha
Session Name Poster Session: Hydrologic, Biogeochemical and Ecological Processes 2
Category Hydrologic, biogeochemical and ecological processes
Poster Number 220
Author(s) Alphonce Guzha,  University of Florida
  Sanjay Shukla,  University of Florida
  Patrick Bohlen, Archbolds Biological Station
  Mark Clark, University of Florida
  Sarah Lynch, WWF
  Providing Environmental Services from an Agricultural Impoundment in South Florida
  The Florida Ranchlands Environmental Services Project (FRESP) aims to design, test and evaluate a market-based program to pay for water storage and phosphorus (P) retention environmental services on ranchlands. The project contributes to the Northern Everglades and Estuaries Protection Program (NEPP) goal to reduce phosphorus loadings to Lake Okeechobee from contributing watersheds. Eight pilot sites were identified and instrumented for quantifying water storage and nutrient retention. Results from a study for a storm water impoundment site are presented here. The site is a 1000 hectare impoundment within a cattle ranch in southwest Florida. Water was pumped from a public canal into the impoundment and outflow was measured at the downstream and returned back into the canal. Nutrient concentrations in the inflow and outflow water were measured. Water budget analyses for one year (July 2008 to July 2009) show total water inflow of 336 cm (205cm pumped from the canal and 131 cm rainfall). Discharge amounted to 112 cm (33%) while losses to evapotranspiration and seepage accounted for 42% (141cm) and 18% (60cm) respectively. An estimated 23 cm (7%) of water was still stored in the impoundment at year end. The maximum surface water storage in the impoundment was 80 cm and use of impoundment for water storage reduced the canal flows by 13%. Approximately 6.3 metric tons of P was pumped into the site and 2.7 metric tons was discharged, indicating a removal of 3.6 metric tons (58% P treatment efficiency) from canal water which would have been discharged to Lake Okeechobee. A nitrogen (N) treatment efficiency of 37% was also achieved. Results from this pilot site indicate that agricultural impoundments can be used as nutrient removal and water storage sites, and therefore help achieve NEPP water quality goals and provide additional income to the landowners for providing these services.