Update to Loxahatchee River Coordinating Council

Update to Loxahatchee River Coordinating CouncilL-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 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 <3 <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 <0.005 <0.005 <0.005

Total Phosphorus 0.006 0.008 0.023

Ortho-Phosphorus 0.006 0.002 0.005

Chlorides 442 614 633

Sulfate 165 229 236

Parameters

(Cell 6)

Sampling Depth

0.5 m 6.5 m 12.5m

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 <0.005

Total Phosphorus 0.010 0.018 0.022

Ortho-Phosphorus <0.002 <0.002 <0.002

Chlorides 943 895 914

Sulfate 347 329 334

ResultsResultsSimilar 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

Site Unit n Average Minimum Maximum

L8MZBN µS/cm 20 768 489 978L8MZBS µS/cm 20 569 480 695

Mixing Zone BoundariesMixing Zone Boundaries

FLOW-WAY 1 TESTFLOW-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 CRITERIATEST CRITERIA

Establish baseline stages/flow rating curvesControl GWP releases to limit effect on apple

snailsRelease ~150 cfs at Control 2, 100 cfs at G-161,

100 cfs to NWFLRMaintain appropriate stages at GWP, G-161 and

G-160Ensure coordination with stakeholdersMeasure water flow at critical locationsObtain water quality samples during test

Establish baseline stages/flow rating curvesControl GWP releases to limit effect on apple

snailsRelease ~150 cfs at Control 2, 100 cfs at G-161,

100 cfs to NWFLRMaintain appropriate stages at GWP, G-161 and

G-160Ensure coordination with stakeholdersMeasure water flow at critical locationsObtain water quality samples during test

RESULTSRESULTSDATE Calculated Daily average flow (cfs)

CTRL 2 G-161

G-160 G-92 Lainhart Dam

7/1/08 147 41 73 110 128

7/2/08 147 91 160 138 200

7/3/08 143 50 206 71 215

DATE Flow Station

Ctrl 2 G-161 G-160 E. Perimeter

Canal7/2/08 150 - 100 35

7/3/08 - 95 80 -

Measured FlowsMeasured Flows

Measured Avg. Daily Water Levels

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

ConclusionsConclusionsConfirmed 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 ReplacementG-92 Structure Replacement

G-92 StructureProposed Design & Location

G-92 StructureProposed 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 StructureBackground

G-92 StructureBackground

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 StructureBenefits of New Structure

G-92 StructureBenefits 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 StructureOperation

G-92 StructureOperation

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

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 - 300 days

Bid opening scheduled for September 29, 2008 at 2:30 p.m.

Construction start – late November to early December 2008

Construction time frame - 300 days