1. Update to Loxahatchee River Coordinating Council
L-8 Reservoir Water Quality
Flow-way 1 Water Delivery Test
G-92 Structure Replacement
September 29, 2008

2. L-8 Reservoir – August 2007

3. Parameters
(Cell 3)
Sampling Depth
0.5 m
6.5 m
12.5m
Temperature
27.7
23.4
21.9
D.O.
8.83
6.79
4.39
Specific Conductance
2853
2817
2816 pH
8.3
8.1
7.8
TSS
<3
TDS
1649
1644
1328
TKN
.81
.97
.87
Tot. Kjeldahl N
0.81
0.97
0.87
Nitrate/Nitrite
<0.005
0.123
0.130
Ammonia
Total Phosphorus
0.006
0.008
0.023
Ortho-Phosphorus
0.002
0.005
Chlorides
442
614
633
Sulfate
165
229
236

4. 0.5 m 6.5 m 12.5m Parameters (Cell 6) Sampling Depth Temperature 27.9
23.4
22.3
D.O. 10
7.36
5.01
Specific Conductance
3801
3809
3835 pH
7.9
7.7
7.6
TSS 5 3
<3
TDS
2275
2247
2317
TKN
1.12
1.07
1.15
Tot. Kjeldahl N
1.0
0.86
0.84
Nitrate/Nitrite
0.118
0.206
0.308
Ammonia
<0.005
0.009
Total Phosphorus
0.010
0.018
0.022
Ortho-Phosphorus
<0.002
Chlorides
943
895
914
Sulfate
347
329
334

5. 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

6. Mixing Zone Boundaries
Site
Unit n
Average
Minimum
Maximum
L8MZBN
µS/cm 20
768
489
978
L8MZBS
569
480
695

7. 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

8. Grassy Waters Preserve – M Canal
Flow-way #1
G-160
Northlake Bridge
Control #2 Pump Station
G-161
M Canal Widening
Grassy Waters Preserve – M Canal

9. 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

11. Calculated Daily average flow (cfs)
RESULTS
DATE
Calculated Daily average flow (cfs)
CTRL 2
G-161
G-160
G-92
Lainhart Dam
7/1/08
147 41 73
110
128
7/2/08 91
160
138
200
7/3/08
143 50
206 71
215

12. Measured Flows DATE Flow Station Ctrl 2 G-161 G-160 E. Perimeter Canal
7/2/08
150 -
100 35
7/3/08 95 80

13. Measured Avg. Daily Water Levels
DATE
Stage Elevation (feet NGVD)
GWP (G-161 HW)
G-161 TW
G-160 HW
7/1/08
18.18
16.14
15.03
7/2/08
18.04
17.12
15.13
7/3/08
18.15
17.10
14.98

14. 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

15. G-92 Structure Replacement

16. 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

17. 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

18. G-92 Structure Benefits of New Structure
Reliability
Extended service life
Remote operation
Public safety
Flood protection
Water delivery

19. G-92 Structure Operation
New structure will not deviate from existing operational criteria.
Remote operation through telemetry

20. 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