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Johns River Water Management District Comprehensive 5 -Year Plan (spreadsheet) as a priority project for funding during year 3 (FY2000) (Appendix 5, IRLCCMP, revised 1998). ESTIMATED POLLUTANT LOAD REDUCTION : The project is estimated to be consistent with the Indian River Lagoon Program goals of an 80% reduction in pollutant loads and no increase in peak discharge rates for either the mean annual or 25 -year/24-hour storm events for the East Gifford area. PROTECT OBJECTIVES : In 1994 , Woodward-Clyde, consultants under contract to the Indian River Lagoon National Estuary Program (IRLNEP), published eight volumes of technical reports describing the historical data reviewed, their assessment of the data and its reliability. The three reports considered pertinent for Indian River County are the following Status and Trends Summary of the Lagoon, The Preliminary Water and Sediment Quality Assessment of the Indian River Lagoon, and Loadings Assessment of the Indian River Lagoon . In these volumes of literature, the Indian River County area of the Lagoon (from Sebastian Inlet to the St. Lucie County) is designated by Woodward Clyde as Segment-3 (Appendix 4) . Segment 3 , known as the South Central Indian River Lagoon basin, is further divided into 23 sub-basins within the basin. The largest pollutant loadings in this segment are contributed by the large basins that have been extended by ditching and major canal systems, as has occurred in the East Gifford project area. When compared to other segments throughout the Indian River Lagoon region, it was calculated by Woodward-Clyde that Segment 4 (St. Lucie County area) accounts for the highest segment-wide pollutant loads, followed by Segment 3 the Indian River County area. Woodward-Clyde noted that the project vicinity has among the highest area loading rates far the entire water body. Woodward- Clyde attributes these high loadings to the intense agricultural uses or the combinations of urban and agricultural development. Woodward-Clyde listed priority issues for the Lagoon as follows : ( 1 ) reduction of stormwater runoff loads from the urban areas; (2) the initiation of studies to determine if septic tanks are impacting the Lagoon by contributing fecal coliform and excess nutrients; (3) the retrofitting of stormwater systems in developed urban areas including US Highway 1 ; and (4) the use of best management practices (BMPs) in stormwater treatment. To conclude, in Segment 3 , the effects of salinity values on the Lagoon are significant. In the project area salinity drops to about 26.0 ppt near Vero North, Main and South Canal outfalls . This part of the Lagoon has a small surface area so evaporation is reduced as well. Another example of the effect of the freshwater discharge into this segment is color. According to Woodward-Clyde, wet season color values are higher than dry season values by a factor of 3, indicating discharge of colored, tannin-laden waters during wet season stormwater and groundwater flow. Total phosphorus values around the three Vero canal discharge points (South, main and North canals, as well as at the Sebastian River, the Felismere Canal and C-54, are substantially higher than elsewhere in the Lagoon. Total Kjeldahl nitrogen is also elevated in this portion of the Lagoon between Wabasso and Vero Beach. Activities proposed in Indian River County' s Surface Water Management Plan are expected to reduce solids, sediments, organic matter, fresh water and nutrients discharged from Indian River County' s stormwater systems. These actions will influence Lagoon trends in a positive direction. To date, Pollutant Load Reduction Goals (PLRGs) have not been established for the Indian River County area or for other waters in the vicinity. The St. Johns River Water Management District (SJRWMD) has initiated the PLRG development process and is refining the model to develop goals for this area. In June 1999, Indian River County completed its conceptual plan, preliminary environmental site assessment and draft mitigation plan for the project. The problem at East Gifford is relatively easy to define. The frequent flooding of the Gifford area lying east of the one mile coastal ridge can be reasonably attributed to the construction of the Florida East Coast Railroad and to the U. S . Highway 1 roadway. Both transportation corridors were constructed on raised grades which has blocked the historical sheetflow of stormwater runoff from west to east. DEP Agreement No. WM836, Attachment A- 1 , Page 2 of 11