Lake Granbury Overview Water Quality Modeling Update • History of studies on Lake Granbury • Watershed Protection Plans in Texas • Data evaluation – Whole lake – Canal by canal David Harkins, Ph.D., P.E. – Findings Tim Osting, P.E. Espey Consultants, Inc. • Modeling approach February 13, 2007 • Recommendations

Lake Granbury History Watershed Protection Plan • Dam completed in 1969 • BRA study in 1982 •Why? – Reviewed earlier reports (TDWR, USGS) – Existing bacteria concentrations – Development of areas around the lake – Evaluated treatment of septic systems • What is the result? – Evaluated nutrient loads – Partnership • BRA study 1995 – Ensure good water quality – Identified canal systems with high bacteria – Roadmap for all agencies concentrations – Identify all options • Clean Rivers Program special studies 2001-current – Choose the best options – 50 monitoring locations • Golden Alga study

Watershed Protection Plan Examples • Texas • Trinity River Basin WPP – Similarities and Differences – Concho River – Lake Bridgeport – Little Wichita River – Eagle Mountain Lake • Most WPPs address sediment, nutrients – Pecos River –Lake Benbrook – Plum Creek – Cedar Creek Reservoir • Bacteria WPPs usually agricultural or wildlife – Arroyo Colorado – Richland-Chambers Reservoir – Caddo Lake • National sources – Dickinson Bayou – Dungeness River, WA – Hickory Creek – Nooksack River, WA • Some address specific pollutants (eg, atrazine) – Upper San Antonio River – Grand Traverse Bay, MI • Brazos River Basin – Green Valley Lake, IA • All recommend region-wide measures to control – Lake Granger – Lake Bomoseen, VT – North Bosque River – Kezar Lake, NH numerous small sources – Aquilla Reservoir – Lake Waco – Lake Onondaga, NY • Lake Granbury – Belton Lake – Lake Ochechobee, FL – Stillhouse Hollow Lake – Stoney Creek Watershed, MI – Man-made canals – Santa Clara River, CA – No clear-cut agricultural sources – Cuyuga Lake, NY

1 Lake Granbury Pool Elevation (ft) CPE = 693 ft Data evaluation 693 692 691 •Lake 690 689 – No concerns based upon water quality standards 688 687 – Some indication of trends toward eutrophication 686

Elevation (ft) 685 – Dissolved solids 684 • Canals and coves 683

– 4 canals nearing bacteria impairments, 1 site impaired 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 • Concentration is high and is persistent Date • Watershed source not indicated – 1 canal/cove site near Nitrogen screening level Lake Granbury - monthly release compared to capacity Cove data – 4 canal/cove sites do not meet DO standard 1972 ÅSWQM data and special studies CRP data 140 400% 120 350% 100 300% 250% 80 200% 60 150% 40 #capacities / / #capacities 136,823 ac-ft 136,823 100% 20 50% percent of capacity of percent Month's release, as release, Month's 0 0% Jan-85 Jan-86 Jan-87 Jan-88 Jan-89 Jan-90 Jan-91 Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06

Temporal Trend with 95% confidence limits - Lake Granbury Segment 3 - 11862 Temporal Trend with 95% confidence limits - Lake Granbury Segment 3 - 11862 Temporal Trend with 95% confidence limits - Lake Granbury Segment 3 - 11862 Temporal Trend with 95% confidence limits - Lake Granbury Segment 3 - 11862 Chlorophyll a Secchi Depth 7.5 DO deficit 100.00 2.50 18 Dissolved Oxygen (DO)

16 5.0

HEADWATERS 2.00 HEADWATERS 14 HEADWATERS 75.00 HEADWATERS 2.5 12 1.50 10 0.0 50.00 8

CHL'A (ug/L) CHL'A 1.00 -2.5 Secchi depth(m) 6 DO (0-2 meters) (mg/L)

25.00 DO Defecit (0-2 meters)(mg/L) Temporal Trend with 95% confidence limits - Lake Granbury Segment 2 - 11861 Temporal Trend with 95% confidence limits - Lake Granbury Segment 2 - 11861 4 0.50 -5.0 Temporal Trend with 95% confidence limits - Lake Granbury Segment 2 - 11861 Temporal Trend with 95% confidence limits - Lake Granbury Segment 2 - 11861 2 100.00 2.50 7.5 0 -7.5 0.00 0.00 18

16 5.0 1/1/70 1/2/75 1/3/80 1/3/85 1/4/90 1/5/95 1/6/00 1/6/05 2.00 1/1/70 1/2/75 1/3/80 1/3/85 1/4/90 1/5/95 1/6/00 1/6/05 01/01/70 01/02/75 01/03/80 01/03/85 01/04/90 01/05/95 01/06/00 01/06/05 75.00 01/01/70 01/02/75 01/03/80 01/03/85 01/04/90 01/05/95 01/06/00 01/06/05 Date Date Date Date 14 GRANBURY GRANBURY GRANBURY 2.5 GRANBURY 1.50 12

50.00 10 0.0

CHL'A (ug/L) CHL'A 1.00 8 Secchi Depth (m) Depth Secchi -2.5 25.00 6 DO (0-2 meters) (mg/L)

0.50 DO Defecit (0-2 meters) (mg/L) 4 -5.0 Temporal Trend with 95% confidence limits - Lake Granbury Segment 1 - 11860 Temporal Trend with 95% confidence limits - Lake Granbury Segment 1 - 11860 2 Temporal Trend with 95% confidence limits - Lake Granbury Segment 1 - 11860 Temporal Trend with 95% confidence limits - Lake Granbury Segment 1 - 11860 0.00 0.00 -7.5 100.00 0 2.50 1/1/70 1/2/75 1/3/80 1/3/85 1/4/90 1/5/95 1/6/00 1/6/05 18 7.5 Date 01/01/70 01/02/75 01/03/80 01/03/85 01/04/90 01/05/95 01/06/00 01/06/05

Date 01/01/70 01/02/75 01/03/80 01/03/85 01/04/90 01/05/95 01/06/00 01/06/05

16 01/01/70 01/02/75 01/03/80 01/03/85 01/04/90 01/05/95 01/06/00 01/06/05 Date DECORDOVA 2.00 DECORDOVA Date 5.0 75.00 14 DECORDOVA DECORDOVA 12 2.5 1.50

50.00 10 0.0 1.00 8 CHL'A (ug/L) Secchi Depth (m) Secchi Depth 6 -2.5 25.00 0.50 DO (0-2 meters) (mg/L) 4

DO Defecit (0-2 meters) (mg/L) -5.0 2 0.00 0.00 0 -7.5 1/1/70 1/2/75 1/3/80 1/3/85 1/4/90 1/5/95 1/6/00 1/6/05 1/1/1970 1/2/1975 1/3/1980 1/3/1985 1/4/1990 1/5/1995 1/6/2000 1/6/2005 1/1/70 1/2/75 1/3/80 1/3/85 1/4/90 1/5/95 1/6/00 1/6/05 1/1/70 1/2/75 1/3/80 1/3/85 1/4/90 1/5/95 1/6/00 1/6/05 Dt

Fecal coliform cfu/100mls E. coli mpn/100mls 250

Laguna Tres 200 Sky Harbor Station 11861 Alta Vista 150 Hideaway Bay Lake Granbury Mallard Pointe 100 near Granbury Lakewood Hills Parameter, units The Shores 50 Rollinghills Shores Catalina Bay II Arrowhead Shores Western Hills Harbor 0 Oak Trail Shores Harbor Lakes Sunrise Bay 1/6/1997 1/7/1998 1/8/1999 1/9/2000 1/9/2001

Waters Edge 1/10/2002 1/11/2003 1/12/2004 1/12/2005 1/13/2006 1/14/2007 E. coli mpn/100mls City of Granbury, Lambert Branch Date Grand Harbor Fecal coliform cfu/100mls Lake Granbury Marina Addition 250 Sandy Cove JJ. Mathis Nassau Bay South Harbor 200 DeCordova Bend Estates Rough Creek Timber Cove Rock Harbor 150 Montego Bay Scenic View Port Ridglea East Comanche Harbor Port Ridglea 100 Comanche Point Holiday Estates Parameter, units Island Village Nassau Bay II 50 Ports O' Call Ray Lynn Indian Harbor Jackson Heights 0 Canyon Creek

Jackson Estates 0.000 0.200 0.400 0.600 0.800 1.000 1.200 1.400 Texas Utilities 1-day pcp total, in Blue Water Shores

2 E. coli mpn/100mls Fecal coliform cfu/100mls Port Ridglea – all stations 18031 to 18040 1800 1600

Fecal coliform cfu/100mls 1400 1200 Port Ridglea E. coli mpn/100mls 1800 1000 all stations 18031 800 to 18040 1600 600 Parameter, units Parameter, 1400 400 200

1200 0

1000 0.000 0.500 1.000 1.500 2.000 2.500 1-day pcp total, in E. E.coli coli mpn/100mls mpn/100mls

800 1800 600 1600

Parameter, units 1400 400 1200 200 1000 800 0 600 Parameter, units 400 200

1/1/2002 1/2/2003 1/3/2004 1/3/2005 1/4/2006 1/5/2007 0 Date 0.000 0.500 1.000 1.500 2.000 2.500 3.000 3.500 3-day pcp total, in

Nitrite-N mg/L N as NO2

Fecal coliform cfu/100mls Nitrate-N mg/L N as NO3 Fecal coliform cfu/100mls 1.6 E. coli mpn/100mls E. coli mpn/100mls 2500 2500 1.4

2000 18015 2000 18016 1.2

1500 1 1500 Oak Trail Shores

1000 0.8 1000 all stations 18008 Parameter, units 500 units Parameter, 500 0.6

Parameter, units to 18009 0 0 0.4 0.2 12/5/2001 12/5/2002 12/5/2003 12/4/2004 12/4/2005 12/4/2006

Fecal coliform cfu/100mls 12/5/2001 12/5/2002 12/5/2003 12/4/2004 12/4/2005 12/4/2006 Date Fecal coliform cfu/100mls E. coli mpn/100mls E. coli mpn/100mls Date 0 2500 2500 18013 2000 2000 18014 12/5/2001 12/5/2002 12/5/2003 12/4/2004 12/4/2005 12/4/2006 1500 1500 Date Nitrate-NNitrate-N mg/L mg/L N N as as NO3 1000 1000 Parameter, units Parameter, units 500 500 1.6 0 0 1.4

12/5/2001 12/5/2002 Fecal coliform12/5/2003 cfu/100mls 12/4/2004 12/4/2005 12/4/2006 12/5/2001 12/5/2002 Fecal coliform12/5/2003 cfu/100mls12/4/2004 12/4/2005 12/4/2006 1.2 E. coli mpn/100mlsDate E. coli mpn/100mlsDate 2500 2500 1

2000 18012 2000 18011 0.8 E. coli. 0.6 1500 1500

Parameter, units 0.4 1000 Sky Harbor 1000

Parameter, units 0.2 Parameter, units 500 500 stations 18011 0 0 to 180016 0 0.000 0.500 1.000 1.500 2.000 2.500 3.000 3.500 4.000 12/5/2001 12/5/2002 12/5/2003 12/4/2004 12/4/2005 12/4/2006 12/5/2001 12/5/2002 12/5/2003 12/4/2004 12/4/2005 12/4/2006 Date Date 3 -day pcp avg, in

Data Analysis Conclusions • Lake-cove water exchange not well-understood • Bacteria – Problems in some canals, not in lake – Watershed source is not likely •Nutrients – DO, chl a and clarity (secchi depth) show trends – Existence of macrophytes, duck weed, golden algea – Phosphorus trend unclear

3 Watershed Models Watershed modeling

SWAT Comprehensive runoff and constituent model, process-based Soil Water Assessment Tool Agricultural HSPF Comprehensive runoff and constituent model, process-based • To determine what drains into lake waters Hydrologic Simulation Program - FORTRAN Sediment SWMM5 Comprehensive runoff and constituent model, process-based – Stormwater runoff Storm Water Management Model v5 Urban PRMS Comprehensive runoff-only • Watershed, size, topography/drainage patterns and soil Precipitation-Runoff Modeling System WEPP Comprehensive runoff-only characteristics Water Erosion Prediction Project Small-watersheds Soil Conservation Service Curve Numbers Standard runoff-only • No runoff data Load Duration Curves Statistical characterization of bacteria concentration – Constituent of concern (bacteria, nutrients) INPUT DATA REQUIREMENTS CALIBRATION AND VALIDATION DATA • Monthly in-lake concentration data Standard Comprehensive Standard Comprehensive Drainage area Rainfall time-series Flow Flow time-series • Source location and interval between release not known Topography/drainage patterns Infiltration Concentration Concentration time-series Soil characteristics Evapotranspiration Rainfall Wind Pollutant source and concentration Temperature Tillage Erosion/deposition

Lake modeling Lake modeling BATHTUB Steady-state, statistical nutrient model Lakes HSPF Comprehensive runoff and constituent model, process-based • What happens in the water body? Hydrologic Simulation Program - FORTRAN Well-mixed receiving water model; first-order decay; river; 1D QUALTX Steady-state flow and water quality model • Bacteria Segmented; first-order decay; river; 1D • Consider each canal/coves system individually WASP Comprehensive multidimensional water quality analysis Water Analysis and Simulation Package Requires external hydrodynamic model • Source and amount of bacteria contributions CE-QUAL-W2 Comprehensive multi-dimensional water quality analysis • Decay rate Includes hydrodynamics, stratification; Estuaries and lakes CSTR Standard mass-balance model of a well-mixed segment • Concentration influenced by rainfall and circulation Continuously-stirred tank reactor Custom formulation and spreadsheet implementation

•Nutrients INPUT DATA REQUIREMENTS CALIBRATION AND VALIDATION DATA • Characterize current status Standard Comprehensive Standard Comprehensive Inflow Inflow and conc. time-series Concentration Concentration time-series – water and nutrient balance Depth Bathymetry Water movements Tracers Surface area Circulation patterns Flow measurements – identify major sources Water exchange Wind • WASP, CE-QUAL-W2 – multidimensional models Segmentation Temperature Pollutant concentration input Solar radiation – Wind, temperature, water balance Pollutant change or decay Profiles – Temporal and spatial relationships need to be explicitly quantified Pollutant concentration output Processes causing change

Questions? Data needs

• Septic tracer studies • Port Ridglea East, Oak Trail Shores, Sky Harbor, Rollinghills Shores • Lake-to-canal water exchange • Dye tracer with atmospheric and WQ measurements • Port Ridglea East, Water’s Edge, Oak Trail Shores, Sky Harbor, Rollinghills Shores • Bacterial Source Tracking • Monitoring • Additional coves? • Phosphorus tested to low detection limits, at 3 long-term lake stations

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