S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T Draft Guidelines for Suspending Marsh Monitoring Based on Stage Data Pete Rawlik Environmental Resource Assessment Department SFWMD June 30, 2009

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T Rationale The surface water quality samples at internal marsh stations must be representative Previous guidance has defined the lower limits of representative sampling to be a minimum clear water depth of 10 cm A review of sampling records revealed that during dry conditions many marsh stations routinely drop below 10 cm, and are not sampled It may be possible to remotely determine when water depths are too low to sample and abort/reorganize flights

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T WCA2A F1 6/28/07

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T WCA2A U3 6/13/07

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T S178 5/18/09

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T Tambr105 5/18/09

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T Complicating Factors Stage is a measure from a fixed marker to the surface of the water column and should relate strongly to the measurement of depth to consolidated substrate (DCS) Sampling decisions are based on total clear water depth not DCS Periphyton and flocculent layers change depending on stage, season and other environmental factors, and therefore influence the total clear water depth As a result, the prediction of total clear water depth is not easily predicted from stage

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T Stage Depth to Consolidated Substrate (DCS) Sampling Depth Total (Clear) Water Depth Measuring Depth in the Everglades Stage Gage Old Peat New Peat Periphyton Water Column Unconsolidated Flocculent Layer

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T Methodology Compare historical stages to total clear water depth and determine at what stage sampling is no longer successful (<10 cm) In order to simplify the process for end users the number of gages must be kept to a minimum Group stations into large geographic areas if possible Use real-time data when possible, but an average from the previous day is acceptable

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T WCA1 Water quality monitoring in WCA1 is required by the Settlement Agreement Compliance Calculation and the TP Rule Both mandates are subject to a minimum of 10 cm of clear water The Settlement Agreement Compliance Calculation requires that the average stage at gages 1-7, 1-8C, and 1-9 be at or above feet Data from all 3 gages are available hourly on the EDEN website

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T Average stage (1-7,1-8c, 1-9) in WCA1 since January 2005

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T Site Specific Issues 4/18/07 average stage = feet –Three stations were collectable (Lox13=12 cm, Lox11=18 cm, Lox12=32 cm) 6/4/07 average stage = feet –Five stations were collectable (Lox13 & Lox8=12 cm, Lox11 & Lox130 = 14 cm, Lox14=18 cm) 5/5/09 average stage = feet –One station was collectable (Lox12 = 25 cm)

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T Guidance for WCA1 If the mean stage of the three compliance gages is less than feet, sampling in the northwestern section should be suspended If the mean stage of the three compliance gages is less than feet, sampling in the southeastern section should be suspended

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T 3 gage average <15.40 feet 3 gage average <15.00 feet Indicates a station that was no longer collectable below an average stage of feet Indicates a station that was still collectable at an average stage of feet Indicates a station that was still collectable at an average stage of feet

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T WCA2A Water quality monitoring in WCA2A is required by the Settlement Agreement and the TP Rule There are no stage-based requirements for either mandate Both mandates are subject to a minimum of 10 cm of clear water Variation in the topography of WCA2A requires that the area be divided into 4 zones using two stage gages

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T 2-17 gage <11.25 feet 2-17 gage <11.50 feet 2-17 gage <10.75 feet Eden 11 gage <10.80 feet

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T North Quad dry Central Quad dry South Quad dry Recent 2-17 Stage Gage Data

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T Historical 2-17 Stage

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T Historic Eden 11 Stage Minimum sampling stage

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T 10.8 ft Minimum sampling stage

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T WCA3 Water quality monitoring in WCA3 is required by the Settlement Agreement and the TP Rule There are no stage-based requirements for either mandate Both mandates are subject to a minimum of 10 cm of clear water Variation in the topography of WCA3 requires that the area be divided into seven zones using four stage gages

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T 3ANE gage <9.30 feet 3ANE gage <9.90 feet 3AN1W1 gage <10.60 feet S340T gage <8.0 feet S340T gage <7.80 feet S340T gage <7.60 feet 3BS1W1_H gage <5.10 feet

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T How does this help? Using seven stage gages, the water depths in thirteen zones in four conservation areas, can be predicted to be below a minimum sampling depth With this information helicopter flights can be suspended or reorganized to optimize collection and minimize flights that produce no data

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T Historical periods when stage guidance would have suspended sampling in various WCA Zones (1/1/07 to 5/1/09)

S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T Request The SFWMD asks that the TOC review the proposed guidance Comments and alternative guidance including different strategies, gages, stages and criteria are welcome A follow-up discussion will be scheduled for the next meeting