Charlotte H Harbo bor F Flatw twoods s Initi tiati tive - - PowerPoint PPT Presentation

Charlotte H Harbo bor F Flatw twoods s Initi tiati tive Update

Prepared by Roger Copp, Water Science Associates June 20, 2018

Componen ents o s of Cha harlotte H e Harbor Fla latwoods In Init itiative

• Cecil Webb has too

much water

• Historic outflows

blocked

• Downstream wetlands

have plenty of water in wet season, but are too dry in dry season

• Solution: store water for

multiple beneficial uses

• Bond Farm is being converted to a reservoir to reduce high

water conditions in Cecil Webb WMA

• Water stored in Bond Farm Reservoir may be conveyed to

Yucca Pens at end of wet season to extend wetland hydroperiods

• Discussions are underway to obtain a drainage easement

through the McNew Ranch and private land west of U.S. 41

• Bond Farm Reservoir capacity is inadequate to address excess

water in Cecil Webb

Ov Over erview o

• f P

Projec ects U Under nderway

3

• Additional studies of Yucca Pens are being planned to refine

the hydroperiod requirements of wetlands

• Wells recently installed in Yucca Pens WMA
• Ecologic studies of Yucca Pens wetlands have begun
• Modeling work will then be conducted using ecologic and hydrologic

information to evaluate restoration alternatives

• Conversion of the Southwest Aggregates mine to a reservoir

would provide additional storage for excess water in Cecil Webb

• The SW Agg reservoir will only store water that is flooding Cecil

Webb and is not needed in Yucca Pens

• Water from mine reservoir would be piped to Cape Coral to

augment their irrigation water supply

Overview of Projects U Underway, c , cont’d.

4

Maps o s of Study Area ea S Sho howing Water ersh shed eds

Runoff originates in SFWMD, enters SWFWMD, and then re-enters SFWMD

5 Note that most of the drainage basin is in SFWMD

Existing path is to Gator Slough

Water levels in Cecil Webb remain above recommended hydroperiod depths during the wet season

Impact of Bond P Plus S SW A Aggregates

6

Be Benefit o

• f S

Southwest A Aggregates o

• n Ce

Cecil Webb WM WMA

• Reduced water levels are observed in the impacted areas of Cecil Webb

WMA

• Impact of Bond plus SW Agg is greater than reservoir on Bond Farm
• Additional storage

beyond Bond plus SW Agg may be needed

Simulated W Water Levels i in C Cecil W Webb wi with Bond a and SW Agg

• Simulated water levels remain elevated during wet season
• Duration of high water levels longer than optimum
• 1.5
• 1
• 0.5

0.5 1 1.5 2 2.5 3 1/1/11 4/1/11 6/30/11 9/28/11 12/27/11 3/26/12 6/24/12 9/22/12 12/21/12 3/21/13 6/19/13 9/17/13 12/16/13

Depth, ft

Water Depth Relative to Ground Surface

Impacts N Near t the S SW Agg Reser servoir

• Simulated groundwater Levels show normal SW FL seasonal patterns

with no apparent impact from adjacent mining operations to residential neighborhood north of SW Aggregates

Ground El.

Measu sured ed 2 201 017 WLs i s in n Wel ells E s East of Mine ne

• Water levels in MW-E2, 200 ft away from the withdrawal lake, dropped

2 feet due to pumping. No drop at MW-E3, 1500 ft away

• Water level changes will be reduced in future pumping due to hydraulic

barrier

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 15 16 17 18 19 20 21 22 23 24 25 26 4/20/17 4/27/17 5/4/17 5/11/17 5/18/17 5/25/17 6/1/17 6/8/17 6/15/17 6/22/17 6/29/17 7/6/17 7/13/17 7/20/17 7/27/17

Rainfall (inches) Water Level Elevation (ft. NAVD)

Rainfall MW-E1 MW-E2 LM-1 MW-E3

Water B Bala alance Check of

• f Cec

ecil W il Web ebb an and Yucca P Pens

WMA Acres

Cecil Webb areas too wet 10,000 Yucca Pens Wetlands 6,000

• At least 10K AF

available annually.

• Bond Farm is less than

¼ of that amount

• Additional storage and

conveyance is needed

• There’s adequate

water for both Yucca Pens and Cape Coral

Sum ummary o

• f C

Cha harlotte H e Harbor F Flatwoods s Restoration P Plan

• The plan is still in development
• Objective is to reduce problem flooding in Cecil Webb,

augment hydroperiod in Yucca Pens, and provide excess flows to augment Cape Coral water supply

• Only take water into SW Agg when Bond is full and Cecil

Webb still has too much water

• Modeling results suggest storage need exceeds combined

storage volume of Bond + SW Agg

• If hydroperiod need exceeds volume available in Bond, then

additional measures may be needed

Questions?

How S Stored W Water W Will b ill be U e Use sed

• Bond and SW Agg are filled in wet season
• Bond Outflow (20 cfs) is at end of wet season (late October) for

about 2 months

• SW Agg outflow begins in January and can deliver 17 cfs (11 MGD)

for four months

5 10 15 20 25 30 35 6/1/12 8/1/12 10/1/12 12/1/12 1/31/13 4/2/13

cfs

Simplified Reservoir Operations

Flow to Bond flow to SW Agg Bond to YP SW Agg to CC

Estimate o

• f Long-term Availa

ilable le Y Yield eld

• A simulation was conducted from 2007 through 2015
• Inflows during wet season and released to the City in dry season after

Feb 15

• Available yield = 4,600 ac-ft/yr for 8 out of 9 years.
• Irrigation yield 12.5 MGD for 120 days

On-going E g Efforts ts t to Better U Understand Yucca P Pens

• Cape Coral installed five data loggers in south Yucca Pens

and one data logger near Zemel Road and powerline

• Additional borings and monitoring wells are planned to

improve understanding of Yucca Pens hydrology

• Ecologic studies of Yucca Pens wetlands may begin in 2018

to document areas that are too dry

Yuc ucca P Pens ns New Da Data C Collec ection

Operational Hopefully soon