Update to Loxahatchee River Coordinating Council L-8 Reservoir Water Quality Flow-way 1 Water Delivery Test G-92 Structure Replacement September 29, 2008 L-8 Reservoir Water Quality Flow-way 1 Water Delivery Test G-92 Structure Replacement September 29, 2008
L-8 Reservoir – August 2007
Parameters (Cell 3) Sampling Depth 0.5 m6.5 m12.5m Temperature D.O Specific Conductance pH TSS<3 TDS TKN Tot. Kjeldahl N Nitrate/Nitrite< Ammonia<0.005 Total Phosphorus Ortho-Phosphorus Chlorides Sulfate
Parameters (Cell 6) Sampling Depth 0.5 m6.5 m12.5m Temperature D.O Specific Conductance pH TSS53<3 TDS TKN Tot. Kjeldahl N Nitrate/Nitrite Ammonia< <0.005 Total Phosphorus Ortho-Phosphorus<0.002 Chlorides Sulfate
Results Similar to historical for WY 05 – WY 08 Lower concentrations of nutrients in cells than in either L-8 or M-Canal No metals exceeded WQ criteria Class I/III criteria exceeded for: Specific conductance, TDS, Chlorides and Gross Alpha Levels comparable to current cell historical levels – levels of parameters in exceedence are expected to decrease as reservoir is operated Similar to historical for WY 05 – WY 08 Lower concentrations of nutrients in cells than in either L-8 or M-Canal No metals exceeded WQ criteria Class I/III criteria exceeded for: Specific conductance, TDS, Chlorides and Gross Alpha Levels comparable to current cell historical levels – levels of parameters in exceedence are expected to decrease as reservoir is operated
SiteUnitnAverageMinimumMaximum L8MZBN µS/cm L8MZBS µS/cm Mixing Zone Boundaries
FLOW-WAY 1 TEST PURPOSE: To test water delivery from the regional water system to the Loxahatchee River Basin using the existing infrastructure TEST DATE - July 1 – July 3, 2008 PURPOSE: To test water delivery from the regional water system to the Loxahatchee River Basin using the existing infrastructure TEST DATE - July 1 – July 3, 2008
M Canal Widening Control #2 Pump Station G-161 Northlake Bridge G-160 Flow-way #1 Grassy Waters Preserve – M Canal
TEST CRITERIA Establish baseline stages/flow rating curves Control GWP releases to limit effect on apple snails Release ~150 cfs at Control 2, 100 cfs at G-161, 100 cfs to NWFLR Maintain appropriate stages at GWP, G-161 and G-160 Ensure coordination with stakeholders Measure water flow at critical locations Obtain water quality samples during test Establish baseline stages/flow rating curves Control GWP releases to limit effect on apple snails Release ~150 cfs at Control 2, 100 cfs at G-161, 100 cfs to NWFLR Maintain appropriate stages at GWP, G-161 and G-160 Ensure coordination with stakeholders Measure water flow at critical locations Obtain water quality samples during test
RESULTS DATECalculated Daily average flow (cfs) CTRL 2G- 161 G-160G-92Lainhart Dam 7/1/ /2/ /3/
DATEFlow Station Ctrl 2G-161G-160E. Perimeter Canal 7/2/ /3/ Measured Flows
Measured Avg. Daily Water Levels DATEStage Elevation (feet NGVD) GWP (G- 161 HW) G-161 TWG-160 HW 7/1/ /2/ /3/
Conclusions Confirmed that if replacement water is available, structures can be operated to deliver flow Confirmed 150 cfs at control 2, but only 35 cfs at E. perimeter canal G-161 operated to deliver 100 cfs to C-18 Flow to NWFLR exceeded 100 cfs during test period Each structure is critical and operation must be synchronized to achieve results Measured flows agreed with estimated Confirmed that if replacement water is available, structures can be operated to deliver flow Confirmed 150 cfs at control 2, but only 35 cfs at E. perimeter canal G-161 operated to deliver 100 cfs to C-18 Flow to NWFLR exceeded 100 cfs during test period Each structure is critical and operation must be synchronized to achieve results Measured flows agreed with estimated
G-92 Structure Replacement
G-92 Structure Proposed Design & Location New in-kind (single barrel, box culvert) will be installed to maintain flood protection and conveyance Located adjacent to existing structure Existing structure to be demolished New in-kind (single barrel, box culvert) will be installed to maintain flood protection and conveyance Located adjacent to existing structure Existing structure to be demolished
G-92 Structure Background Structure supplies water from the C-18 canal to the Loxahatchee River via the South Indian River Drainage District canal C-14 Erosion and structure deterioration has limited structure capacity Failure of the existing structure became critical during 2004 hurricane season Structure supplies water from the C-18 canal to the Loxahatchee River via the South Indian River Drainage District canal C-14 Erosion and structure deterioration has limited structure capacity Failure of the existing structure became critical during 2004 hurricane season
G-92 Structure Benefits of New Structure Reliability Extended service life Remote operation Public safety Flood protection Water delivery Reliability Extended service life Remote operation Public safety Flood protection Water delivery
G-92 Structure Operation New structure will not deviate from existing operational criteria. Remote operation through telemetry New structure will not deviate from existing operational criteria. Remote operation through telemetry
G-92 Structure Replacement Schedule Bid opening scheduled for September 29, 2008 at 2:30 p.m. Construction start – late November to early December 2008 Construction time frame days Bid opening scheduled for September 29, 2008 at 2:30 p.m. Construction start – late November to early December 2008 Construction time frame days