BIG CYPRESS BASINReport on Tropical Storm Ernesto and

Subsequent High Rainfall EventAugust-September 2006

BIG CYPRESS BASINReport on Tropical Storm Ernesto and

Subsequent High Rainfall EventAugust-September 2006

October 27, 2006 October 27, 2006

TROPICAL STORM ERNESTO

• Moved thru SW FL on August 30th

• No damaging winds• Rainfall exceeded prediction• Residual moisture generated

heavy rainfall for two weeks• Saturated soil conditions caused

runoff beyond the conveyance capacity of the drainage system

• Caused flooding in some residential yards and roads in NGGE

TROPICAL STORM ERNESTO

• Moved thru SW FL on August 30th

• No damaging winds• Rainfall exceeded prediction• Residual moisture generated

heavy rainfall for two weeks• Saturated soil conditions caused

runoff beyond the conveyance capacity of the drainage system

• Caused flooding in some residential yards and roads in NGGE

Rainfall Summary (inches)at Selected Rainfall Monitoring

Stations

Station 8/1-9/25 8/29-9/4 8/30

CR 951 Ext 22.62 8.48 4.01

Coco #3 32.43 8.17 3.52

Golden Gate Fire Station #2

26.49 7.43 3.94

SGGE WX (52nd Ave SE)

29.05 12.79 8.41

Figure 1. Rainfall Station Locations

Corkscrew 20.99

Fakahatchee N 26.72

Col Seminole Park 24.93

CR951 EXT

00.11

0

0.36

0

0.140.24

0.02 0 0 0 0 0

0.99

0.27

2.32

0.050.09

0.32

0.090.070.14

0.050

1.21

0.35

0

0.92

0.38

4.01

0.37

0.56

0.24

2.66

0.26

0.13

0.26

0.01

0.160.04

0.14

0.68

0 0

0.24

0

0.14

1.29

1.02

0.88

0.44

0

0.97

0 0 00

0.5

1

1.5

2

2.5

3

3.5

4

4.5

8/1 8/3 8/5 8/7 8/9 8/11

8/13

8/15

8/17

8/19

8/21

8/23

8/25

8/27

8/29

8/31 9/2 9/4 9/6 9/8 9/10

9/12

9/14

9/16

9/18

9/20

9/22

9/24

Dai

ly R

ainf

all

0

5

10

15

20

25

30

35

Cum

ulat

ive

Tota

l

8/1/06 - 9/25/0622.62"

Coco #3

0 00.16

1.19

0 0.03

0.53

0.01 0 0 0 0 0

0.90.74

1.9

0.010.01

5.22

0.070.02 00.070.010.070.11

0

0.71

0.26

3.52

0.04

0.570.55

3.22

0.010.17

1.09

0 0.05 0 0

2.48

0.02 0 0 0

0.62

0.9

3.1

3.79

0.01 0

0.27

0

1

2

3

4

5

6

8/1 8/3 8/5 8/7 8/9 8/11

8/13

8/15

8/17

8/19

8/21

8/23

8/25

8/27

8/29

8/31 9/2 9/4 9/6 9/8 9/10

9/12

9/14

9/16

9/18

9/20

9/22

9/24

Dai

ly R

ainf

all

0

5

10

15

20

25

30

35

Cum

ulat

ive

Tota

l

8/1/06 - 9/25/0632.43"

Golden Gate Fire Station #2

0 0

0.95

0 0

0.180.17

0.010.01 0 0 00.09

1.42

0.340.39

1.75

0

1.07

0.45

0.95

0.05

0.22

0.01

0.7

0.32

0.05

2.26

0.2

3.91

0.04

0.61

0.02

2.2

0.45

0

0.42

0.01

0.29

00.09

2.7

0.01 0

0.83

0 0.010.02

0.82

1.66

0 0

0.8

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

8/1 8/3 8/5 8/7 8/9 8/11

8/13

8/15

8/17

8/19

8/21

8/23

8/25

8/27

8/29

8/31 9/2 9/4 9/6 9/8 9/10

9/12

9/14

9/16

9/18

9/20

9/22

9/24

Dai

ly R

ainf

all

0

5

10

15

20

25

30

35

Cum

ulat

ive

Tota

l8/1/06 - 9/25/06

26.49"

SGGEWX

0 0.010.2

0 0 0.09

0.75

0.020.010.110 0 0.06

0.33

0.08

1.68

0.31

0

0.320.44

0.240.04 0

2.71

0.510.37

0.01

0.30.27

8.41

0.090.030.07

0.95

2.96

0.030.04 0

0.86

0

0.81

1.91

0.46

0

0.60.71

0.26

0 0.03

0.35

0.01 0 0.090.010.02

1.49

0

1

2

3

4

5

6

7

8

98/1 8/3 8/5 8/7 8/9 8/1

18/1

38/1

58/1

78/1

98/2

18/2

38/2

58/2

78/2

98/3

1 9/2 9/4 9/6 9/8 9/10

9/12

9/14

9/16

9/18

9/20

9/22

9/24

Dai

ly R

ainf

all

0

5

10

15

20

25

30

35

Cum

ulat

ive

Tota

l

8/1/06 - 9/25/0629.05"

CR 951 Ext Coco #3

Golden Gate Fire Station SGGE WX

Daily and Cumulative Rainfall Totals at Selected Monitoring Stations for August & September 2006

Areas of localized and roadway flooding in western Collier County

Areas of localized and roadway flooding in western Collier County

Post ERNESTO

Observations, Issues and Recommendations

Post ERNESTO

Observations, Issues and Recommendations

Issues: Eastward HO

NGGE Single-Family Residences

Development Percentages 2003

Development Percentages 2005

5

5

5

Development Percentages Increase

Comprehensive Watershed Management Plan:

• Develop Watershed Management Plan (WMP) incorporating the BCB’s western Collier WMP to include Secondary and Tertiary Systems

• Prioritize NGGE basin as the first WMP effort• Objectives to include, but not limited to:

• Improvement of conveyance in both the secondary and tertiary systems

• Mitigate cumulative impacts of fill and impervious surfaces created by construction of not only Single-Family Residences, but also commercial property development and infrastructure within the watershed

• Stem wall / piling constructed homes• On-site retention based on amount of fill and

impervious surfaces• Neighborhood-based retention sites• Grade swales to convey flows• Properly place tertiary culverts – flow lines,

inverts, size – maximize and equalize flows• Install cross culverts in restricted areas• Vegetate swales to reduce sedimentation• MSTU / stormwater utility fee

Recommended Measures

Recommendations

• Examination of the removal of parts of Twin Eagles north berm and subsequent downstream effects

• Examination of water levels in proposed development areas

• Explain the importance of system maintenance and responsibilities to HOAs

• Assess the feasibility of MSTU for Rock Road area

• Explorer Acre-maker Rd relief using pump through Crystal Lakes development to CR 951 Canal

• Assess removal or properly size Cocohatchee culverts under the access road between Quarry and Bonita Bay East Golf Course.

• Place sand bags/sluice gates at wildlife crossing to prevent peak flows from flowing south

• Examine Massey Road drainage ditch

Issues: Planned Unit and Private Development Areas

Issue Areas

• Twin Eagles

• Waterways

• Rock Road / Old Florida Golf Course

• Acre-maker Road / Crystal Lakes

• Massey Road

• Corkscrew Canal Area

• Frangipani Avenue Area

Solutions

• Install culverts to equalize flow levels and move water toward a pump station used for emergency purposes only

• Incorporate high elevations in road designs to prevent sections of road from becoming submerged

• Incorporate Action Plans and responses to potential storm events into road construction permits/plans

Issue Areas• Immokalee Road

• Rock Road

• Randall Boulevard area

• Everglades Boulevard

Issues: Roads and Road Construction

Partially Blocked Culvert Under Immokalee Road

Recommendations• Improvements to Golden Gate Weir #2 to provide

additional of conveyance during storm events

• Relocate and upgrade of Golden Gate #3 for a diversion to Henderson Cr, restore historic flows

• Diversion of approx. 400 cfs to historic North Belle Meade watershed

• Retrofit of Golden Gate Canal Weir# 6 and #7

• Stormwater ASR wells with GG Canal flows

• Modification of steel gate supports on Miller Canal Weir #1 and Faka Union Canal Weir #2 structures

• Monitor wet season GW levels and adjust gate operation for unanticipated major storm events.

• Evaluate the efficiency of the secondary system of structures and implement modifications per WMPs

• Assure protection of natural resources, including the receiving bays, based on permit requirements

Structures• Golden Gate Weirs #2, #3, #6, #7

• Miller Weir #1

• Faka Union Weir #2

• County secondary structures

Issues: Water Control Structure Upgrades & Operation

Golden Gate Weir #5 Submerged

Recommendations

• Hyacinth barriers used to force floating vegetation to the sides of the canal where it could then be mechanically removed and disposed

• Use the ‘T-Bar’ attachment for the Aquamogs to mechanically harvest high density weeds or problem areas

• Utilize a Tow Boat in the larger canals to drag vegetation up from the bottom of the canal, pushed downstream to a collection point and mechanically removed from the canal and disposed

Problem Plants• Floating Hearts (Nymphoides peltata)

• Hydrilla (Hydrilla verticillata)

• Torpedo Grass (Panicum repens)

• East Indian hygrophila (Hygrophilapolysperma)

• Other nuisance grasses

Issues: Vegetation Management

Mechanical Removal of Vegetation

Recommendations• BCB and County staff to do a better job of

trash removal in respective systems

• Contractors required to remove trash

• Add debris collectors to ends of swales in tertiary system

• Require debris grates at the ends of each driveway culvert

• Develop measures to address construction debris

• Work with non-governmental groups, like Keep Collier Beautiful, to support existing, underfunded ‘clean-up’ programs

Issues• Accumulate at water control

structures and other permitted structures, such as docks, bridges and culverts, severely impeding flows

• Cause boating hazards in navigational waterways

• Have effect on public recreational areas, including swimming areas

• Damage environmental resources, such as seagrass beds and mangrove shorelines

• Impact ambient wildlife

• Create aesthetic impacts for residents and visitors

Issues: Gross Pollutants

Gross Pollutants Near Corkscrew Canal

Public Education and OutreachPublic Education and Outreach

• Convey system limitations to public

• Provide Technical Assistance property owners to improve and maintain their stormwater conveyance system

• Conduct public education programs like ‘Know the Flow’ in conjunction with County

• Manage an Interagency Phone Bank during the wet season to provide accurate information for public inquiries

• Continue work with Keep Collier Beautiful and Collier County’s Stormwater Department to promote the Adopt-A-Canal Program

• Actively participate in Keep Collier Beautiful ‘Litter Bugs Me’campaign

• Convey system limitations to public

• Provide Technical Assistance property owners to improve and maintain their stormwater conveyance system

• Conduct public education programs like ‘Know the Flow’ in conjunction with County

• Manage an Interagency Phone Bank during the wet season to provide accurate information for public inquiries

• Continue work with Keep Collier Beautiful and Collier County’s Stormwater Department to promote the Adopt-A-Canal Program

• Actively participate in Keep Collier Beautiful ‘Litter Bugs Me’campaign

Challenges:Challenges:Balancing Flood Control, Water Supply and the Environment!