Introduction. Study Area. Study Area. Monitoring Locations. Watershed Monitoring

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1 Introduction Watershed Influences and In-Lake Processes a Regional Scale Approach to Monitoring a Drinking Water Reservoir, Lake Houston, TX -by M.J. Turco, J.L. Graham, and T.D. Oden Description of study area Watershed monitoring In-Lake monitoring Preliminary evaluation Prepared in Cooperation with the City of Houston 2 Study Area Study Area Lake Houston located northeast of downtown Houston, TX Man-made reservoir with small contributing watershed Significant source water for Houston (pop. 4.5 mill) Drainage area 2,835 mi 2 Landuse is rural, transitional and urban West Fork predominately Urban East Fork predominately Rural 3 Figures from Sneck-Fahrer (2005) 4 Monitoring Locations Two sites selected above Lake Houston Spring Creek near Spring, TX Drainage area: 409 mi2 Streamflow data: 1939-present Water-quality data: 1999-present E. Fk. San Jacinto River near New Caney, TX Drainage area: 388 mi2 Streamflow data: 1984-present Water-quality data: ; 2005-present 5 6 1

2 East Fork San Jacinto River near New Caney, TX 7 Spring Creek near Spring, TX 8 Monitoring Locations Three locations chosen in southwestern quadrant of lake Nearby drinking water raw intake Current set-up provides information at, upstream, and downstream of intake 9 10 Lake Houston site B (near intake) monitoring mechanism 11 Lake Houston Site B (near intake) 12 2

3 Approach Continuous waterquality monitoring Turbidity, Dissolved Oxygen, Temp., Spec. Cond., and ph Discrete sampling Nutrients, sediment, and others Approach Continuous water-quality monitoring Turbidity, Dissolved Oxygen, Temp., Spec. Cond., ph, chlorophyll, blue-green algae, PAR Discrete sampling Nutrients, Geosmin, MIB, Phytoplankton (species), and others Figure from real-time estimation data (USGS - KS) Lake Houston Site B and inflow turbidity data 15 Lake Houston Site B and inflow turbidity data (zoom) 16 Lake Houston Site B and inflow Specific Conductance data 17 Lake Houston Site B and inflow Specific Conductance data (zoom) 18 3

4 Preliminary Results In-lake processes Continuous vertical profile data Stratification Rapid mixing Preliminary Results In-lake processes Lake Houston site B vertical profile data 19 Lake Houston site B Dissolved Oxygen data 20 Preliminary Results In-lake processes Phytoplankton Analysis Seasonal patterns in cyanobacterial biovolume were also similar among sites, although peak biovolume was observed in mid-august at Site B and late- September at sites A and C (a) The biovolume of potential tasteand-odor producers was significantly greater (ANOVA by site and date, p=0.03; depths treated as replicates) at Site A than Site B during late September (b) Biovolume of Potential Taste-and-Odor Producing Cyanobacteria ( mm 3 /ml) Total Cyanobacterial Biovolume ( mm 3 /ml) 3e+6 2e+6 1e+6 4/1/2006 3e+6 2e+6 1e+6 0 a b 5/1/2006 6/1/2006 7/1/2006 8/1/2006 9/1/ /1/ /1/ /1/2006 Site A Site B Site C 1/1/2007 2/1/2007 3/1/2007 4/1/2006 5/1/2006 6/1/2006 7/1/2006 8/1/2006 9/1/ /1/ /1/ /1/2006 1/1/2007 2/1/2007 3/1/2007 Lake Houston site B Dissolved Oxygen data (zoom) Conclusions Conclusions Mobile multi-depth lake water quality monitoring gages are a viable method for collecting and transmitting data When combined with watershed water-quality information the effects of watershed influences on the water-quality in the lake can be evaluated at multiple scales Discrete sampling for ancillary constituents can be used to develop methods by which to estimate loads and possibility of occurrence Water-quality techniques developed through this project can be scaled and modified to fit most project needs

5 Watershed Assessment Team Contact Information Mike Burnich Jeff East Jennifer Graham Limnologist (USGS KS) Matt Milburn Tim Oden Ken VanZandt Reed Green Limnologist (USGS AR) Michael Lee Michael Turco USGS Texas Water Science Center Gulf Coast Program Office The Woodlands, Texas Michael J. Turco