For Santa Fe Springs Working Group Meeting May 19, 2011 in O’Leno State Park Florida

Statistical Evaluation Of Long Term Groundwater Level In Northeastern Florida And Southern Georgia This project involved compilation and statistical trend analyses of historic hydrologic data (groundwater levels, rainfall, streamflow) in Suwannee River Basin counties of Florida and Georgia from 1980 to 2007

Also analyzed GW in northeast FL counties

SPRINGSHEDS Ichetucknee and Santa Fe springs SPRINGSHEDS Ichetucknee and Santa Fe springs

Number of Stations 132 groundwater levels (SRWMD, SJRWMD, USGS) – Includes NE Florida wells from SJRWMD – ONLY wells in the Floridan aquifer 44 rainfall stations (NCDC) 22 streamflow stations (USGS)

Data Compilation Data combined into annual calendar year time series for the period 1980 to 2007 Annual average time series were used for groundwater & streamflow – GWL: 20 years of data with at least 2 measures / year – Streamflow: 10 years of daily averages Total annual inches time series were used for rainfall Rain: 20 years of data with at least 8 monthly total / year Additional groundwater level data in northeast Florida and southeast Georgia were added (request from SJRWMD).

Statistical Trends LOWESS – graphical evaluation to determine if monotonic or piecewise (Cleveland, 1981) Trend detections (for both monotonic and piecewise) were conducted using Mann-Kendall test (Hamed, 2008; Hamed and Rao, 1998) Confid levels: – > 95%, very certain (there is a trend) (p-value < 0.05) – > 90%, probably trending (p-value < 0.10) – > 80%, possible (p-value < 0.20) – < 80%, no trend detected

Monotonic Very certain downward Slope = 1.38 ft/yr p-value = 0.014

Monotonic No Trend Detected p-value = slope = ft/yr

Piecewise 1 st section: Very certain upward p-value = slope = 1.38 ft/yr 2 nd section No Trend Detected p-value = slope = ft/yr

7 USGS - GW level

52 SRWMD – GW level

73 SJRWMD, USGS - Groundwater level Upward trend

22 NCDC – rainfall No trends

22 NCDC - rainfall 1 trending down Dixie

2 rain stations NO trend P-value = 0.22 Trend P-value = 0.01

9 USGS – streamflow No trends

13 USGS – stream flow No trends

GW Trend Results Significant trends (conf level > 85%): 12 wells in SRWMD 5 USGS wells in Georgia 28 SJRWMD wells All were downward except one in St. Johns County.

Counties with Signif GW reduction Georgia – Worth, Tift, Cook Florida (SRWMD) – Baker, Bradford, Lafayette, Union

Water Use data estimation from 1980 to 2007 in millions of gallons per year. Agric from USGS = Agricultural calculated by USGS every 5 years using estimated irrigated crop acreage mul­tiplied by a use coefficient from selected crop irrigation models; Agric we calculated = estimated crops reported by NASS * recommended irrigation for that crop DomSelfSup = Domestic Self-Supply (USGS calculates using statewide per capita water use rate * population not using public supply) ¥ ; PubSupp = Public Supply (from monthly permittee reporting); Comm Ind Pow = Industrial/commercial/mining/power (from monthly permittee reporting).

7 USGS - GW level

Water Use estimation data

Tift County Georgia

Water Use estimation data Cook County Georgia

52 SRWMD – GW level

Water Use estimation data Baker County Florida

Water Use estimation data Bradford County Florida

Water Use estimation data Lafayette County Florida

Water Use estimation data Union County Florida

Water use data 5 year reports done by Rich Marella at USGS:

Water Use: important & not easy! Here is what Agriculture estimates look like when we try to do them:

Water Use: important & not easy! Here is what Agriculture estimates look like when we try to do them:

Thank you! Kathleen McKee Reports online: SP12.pdf SP11.pdf