Determination of Nutrient Loads to East Coast Canals

The objextives of this project were threefold: 1) to determine if historical water-quality data collected as grab samples at 0.5 and c1.0 m below the surface near the centroid of flow adequately represent stream cross-sectional chemistry, 2) to develop reliable estimates of nitrogen and phosphorus loads for east coast canals based on statistical models developed from utilizing the techniques of ordinary least squares regression, and 3) to summarize water-quality data and determine temporal trends for water-quality constituents at two sites that are strategic to Biscayne Bay and the south Florida ecosystem. During phase 1 of the project an intensive field sampling and data collection effort was undertaken. Depth-integrated samples were collected by the equal-width-increment method as well as grab samples at each canal. During Phase 2 data analysis was done.

Nutrient data were collected upstream of 15 coastal control structures in Miami-Dade County. Samples were collected over a typical hydrologic period during various flow conditions. Sampling began at 5 sites in May 1996 and at 10 sites in October 1996. Constituents collected included ammonia, nitrite, nitrate, orthophosphate, and total phosphorus.