And Andrew rew Suthe utherland land, , PhD hD MF MFLs - - PowerPoint PPT Presentation

• St. Johns River Water Management District

And Andrew rew Suthe utherland land, , PhD hD

MF MFLs Technical Program m Ma Manager Division of Wa Water Supply Planning and Assessme ment

Water management districts must establish MFLs that set…

“…the limit at which further withdrawals would be significantly harmful to the water resources or the ecology of the area.”

Section 373.042(1), Florida Statutes (F.S.)

Statut utor

• ry Dir

irect ectiv ive

Statut utor

• ry Dir

irect ectiv ive

“…consideration shall be given to… non-consumptive uses, and environmental values…” 62-40.473, F.A.C.

• Recreation in and on the water
• Fish & wildlife habitats and the passage of fish
• Estuarine resources
• Transfer of detrital material
• Maintenance of freshwater storage &

supply

• Aesthetic and scenic attributes
• Filtration / absorption of nutrients &

pollutants

• Sediment loads
• Water quality
• Navigation

SJRWMD MFLs

MFLs Determination

• Determine the most critical environmental features to

protect and the minimum hydrologic regime required for their protection (MFLs condition)

MFLs Status Assessment

• Determine the baseline hydrologic regime that

represents current conditions (Baseline condition)

• MFL and Baseline conditions are compared to

determine water available

amount available for withdrawal (sustainable yield) Baseline condition amount needed to sustain surface water environment and beneficial uses MFL condition

Time Lake Level / River Flow

MFLs Determination

Lake

IH: upland encroachment FH: wetland inundation MA: organic soils FL: wetland regeneration IL: fish passage

Protect Natural Flow/Stage Variability Communities and Species adapted to High and Low Events

MFLs Determination

MFLs are Events Magnitude, Duration and Frequency

Time Water Level

target elevation

flooding events of varying duration and frequency drying events of varying duration and frequency

Marsh TZ Hardwood Swamp HH Upland

mean elevation of swamp

Frequent Flood Event Magnitude: HS mean elev. Duration: ≥ 30 days Return Interval: 2 years Critical Event: frequent flood needed to maintain extent of hardwood swamp

MFLs Determination

MFLs FLs Status us Asses essment ment

Current Status of MFLs

• Use long-term hydrologic model simulations
• Groundwater model used to determine effect of current

pumping

• Compare the frequency of a critical events
• Baseline Condition vs MFLs Condition
• Determine water availability (freeboard) or deficit

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Future Status of MFLs

• Use 20-yr projected ground water use
• Groundwater model used to determine effect of projected

pumping and remaining freeboard

Surface water and Groundwater Models Key for Assessment

Are MFLs met under 2035 water demand?

Prevent ention & ion & R Reco ecover ery Strategies gies

No action required Are MFLs met under current water demands? Yes Prevention strategy Recovery strategy No Yes No

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Upper Upper Oc Ocklaw klawaha aha Riv iver er Bas asin in (UOR UORB) Lak Lakes es MFLs FLs

Lake Griffin Wekiva River at SR 46 Little Wekiva River and associated springs Rock Springs Wekiwa Springs

2019

Harris Chain

• f Lakes

(Beauclair, Dora, Eustis, and Harris) Lake Apopka

DRAFT

DRAFT

Environme mental Analyses

• Fieldwork complete
• WRVs analyses - ongoing

Mo Modeling

• Calibrated model:
• Peer reviewed
• Updates near completion
• MFLs assessment - ongoing

UOR UORB Lak Lakes es M MFLs FLs

DRAFT

• Post model peer review responses to website… June 2018
• External peer review of UORB MFLs report …... March 2019
• Notice of Rule Development …………………...... October 2019
• Rulemaking workshop ……………………………. November 2019
• Notice of Proposed Rule …………………………. December 2019
• Est. Dates

Ne Next xt S Steps eps

Questions ?