Freshwater Inflow to Tampa Bay Why do we care ? - Circulation and material transport - Salinity and water quality, linkage to nutrient loading and biological resources (seagrasses, benthos) - Fisheries production OTB HB MTB BCB LTB TCB MR Gaged ~ 65 % Of watershed area Gaged and ungaged basins Total Yearly Inflow to Bay Total Source m3/year x 10 6 % of Total Rainfall 1,349 39% Point sources 293 8% Ground water 107 3% Streamflow and 1,741 50% ungaged runoff Total Yearly Inflow to Bay Total % of Total Source m3/year x 10 6 w’out Manatee R. Rainfall 1,349 39% 43% Point sources 293 8% Ground water 107 3% Streamflow and 1,741 50% 44% ungaged runoff Percentages of total streamflow + point sources 12% 38% 17% 5% 3% 1% 24% Percentage of Yearly Rainfall and Streamflow by Month for the Alafia River Basin 20 20 18 Rainfall 18 16 Streamflow 16 14 14 12 12 10 10 8 8 6 6 Rainfall (%) 4 4 Streamflow (%) 2 2 0 0 Jul Oct Jan Dec Feb Apr Jun Mar May Aug Nov Month Sept Dry Wet Hydrodynamic models of river and sub-bays • Lower Hillsborough River - SWFWMD, HydroQual, Inc. • Lower Alafia River - SWFWMD • Tampa Bypass Canal and McKay Bay – USF, HydroQual, Inc. • Little Manatee River – FSU/FAMU • Manatee River - SWFWMD , USF Little Manatee River Model Grid System A. April 20, 2000;Salinity Inflow to Distributions, upper estuary April = 73 20, cfs 2000 (~ 92% exceedance) 1 8 6 4 2 0 22 24 1 12 18 6 14 2 20 10 0 -1 26 2 28 8 6 4 2 2 2 6 4 1 1 1 2 -2 6 4 0 1 0 2 0 6 2 -3 4 -4 6 Elevation (m) -5 4 -6 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 -7 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 River KM F. July 27, 2003; Salinity Inflow to Distributions, upper estuary July = 611 27, 2003cfs (14% exceedance) 1 0 6 4 2 0 8 0 1 14 -1 1 2 12 0 6 4 -2 6 1 6 4 -3 -4 Elevation (m) -5 -6 0 2 4 6 8 1012141618202224262830 -7 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 River KM Alafia River - Gaged and Ungaged ( ) Basins Freshwater inflows – Needs for improved modeling applications • More streamflow gages? Assess cost, accuracy, and utility • Quick access to rainfall and streamflow data, either real-time or retrieved within days or weeks • Reasonably accurate hydrologic models to estimate ungaged runoff to the bay – precision vs. effort and turnaround • Improved rainfall networks needed to support ungaged runoff estimation, regardless of modeling method • More refined runoff and estuarine models for rivers and sub-bays • Improvements in matching basin delineations with estuarine model input nodes for freshwater inflows.