Water Resources Engineering by David R. Maidment

1. Water Resources Engineeringby David R. Maidment • The challenges • floods, droughts, poor water quality • What we are doing about them • engineering structures, better planning, management • What we study • Academic Program at UT

2. Flooding Manawatu, New Zealand http://www.ourregion.co.nz/home.php

3. Bridges that Work http://www.ourregion.co.nz/home.php

4. Bridges that don’t work Small bridge on a country road is washed away http://www.ourregion.co.nz/home.php

5. http://www.tsarp.com/ Most costly urban flood disaster in the history of the United States

6. Major Highways during Tropical Storm Allison I-10 West I-45 South http://www.chron.com/content/chronicle/special/01/flood/

7. Kayaking on US 59, Houston(Tropical Storm Allison) http://www.chron.com/content/chronicle/special/01/flood/

8. Residential Flooding in Tropical Storm Allison http://www.chron.com/content/chronicle/special/01/flood/

9. The Human Cost Saving the wedding photos Cleaning out the car http://www.chron.com/content/chronicle/special/01/flood/

10. 5-day rain total (Tropical Storm Allison) City of Houston Harris County

11. 12-hour rain total(Tropical Storm Allison)

12. Extreme Rainfall Statistics(Tropical Storm Allison)

13. 73,000 houses and apartment buildings flooded

14. Watersheds Stream gaging station Watershed = area that drains to a particular river or stream network

15. Floodplain maps(White Oak Bayou, Houston)

16. What can we do about floods? • Engineering structures • Dams and detention ponds to hold back flood waters • Increase capacity of streams to carry floods • Better flood planning • Create floodplain maps to define at-risk areas • Restrict building foundations are at least 1 foot above 100-year flood elevation • Develop flood forecasting and warning systems

17. Regional Storm Water Modeling Program and Master Plan for San Antonio City of San Antonio

18. San Antonio Regional Watershed Modeling System Geospatial Data: City, County SARA, other “Bring the models together” Modeling System Rainfall Data: Rain gages Nexrad Calibration Data: Flows Water Quality Floodplain Management Capital Improvement Planning Water quality planning Integrated Regional Water Resources planning Flood Forecasting

19. FLOODPLAIN MAP Nexrad Map to Flood Map in Arc 9 Model Builder Flood map as output Model for flood flow HMS Model for flood depth Nexrad rainfall map as input

20. 3D Terrain Modeling

21. Floodplain Mapping: 3-D View

22. Water Supply and Droughts http://agnews.tamu.edu/drought/pics.html

23. http://agnews.tamu.edu/graphics/drought98/TXrainAprJun98BG.htmlhttp://agnews.tamu.edu/graphics/drought98/TXrainAprJun98BG.html

25. Streamflow Conditions http://tx.waterdata.usgs.gov/nwis/rt

26. What can we do about droughts and water supply issues? • Water resource development • Reservoirs and well fields to supply water • Better water resources planning • Senate Bill 1 (1997 Legislature) established 14 water planning regions in Texas • Water Availability Modeling • Drought forecasting (El Nino – Southern Oscillation)

27. Improvements from Senate Bill 1:Water Modeling and Planning • Before Senate Bill 1, water planning was done state-wide by TWDB • SB1 established 14 water planning regional groups, who are now responsible for planning water supply in their area Water Availability Modeling (TNRCC)

28. Sulphur Brazos Trinity Colorado Rio Grande City of Austin Nueces Improvements from Senate Bill 1: Water Availability Modeling 8000 water right locations 23 main river basins Inform every permit holder of the degree of reliability of their withdrawal during drought conditions (TCEQ)

29. CRWR Mission for Senate Bill 1 • CRWR (UT Austin) aids in the response to Senate Bill 1 by providing to TCEQ watershed parameters defined from geospatial data for each water right location • These data are input by TCEQ contractors to a Water Rights Assessment Package (developed at TAMU) which determines the % chance that the water will actually be available at that location • TCEQ sends theownerof the water right a letter specifying the availability of water

30. Water Rights in the Sulphur Basin Water right location Stream gage location Drainage areas delineated from Digital Elevation Models are used to estimate flow at water right locations based on flow at stream gage locations

31. Water Quality

32. Background of Clean Water Act • 1972 Clean Water Act prohibits any discharge of pollutants without NPDES permit - (fishable and swimmable) • 1987 Clean Water Act amended to require NPDES permits for stormwater discharges • Permits require implementation of Best Management Practices (BMPs) to reduce pollutant discharges to “Maximum Extent Practicable”

33. Location of Impaired Waters

34. Austin Area Impaired Water Segments • Bull Creek – Impaired macrobenthic community • Onion Creek – Depressed dissolved oxygen • Slaughter Creek – Impaired macrobenthic community • Waller Creek – Impaired macrobenthic community • Eanes Creek – Bacteria • Gilleland Creek – Bacteria • Taylor Slough – Bacteria • Spicewood Creek - Bacteria

35. What can we do about water quality? • Water quality enhancement structures • Sand filters, wet ponds • Screening inlets to storm sewers • Total maximum daily load (TMDL) • Comes from Clean Water Act • Pollution load that a water body can accept and still maintain its beneficial uses (aquatic life support, recreation, water supply)

36. Requirements for Structural Best Management Practices (BMP’s) • City of Austin – Required since 1981, mainly sand filters • TCEQ – Requires removal of 80% of sediment in stormwater for Edwards Aquifer • LCRA – Requires 70-75% removal of sediment, phosphorus, and oil & grease for Highland Lakes

37. TxDOT Sand Filter

38. Central Park Wet Pond (Austin)

39. Extended Detention Basin

40. Nueces Bay Zinc in Oyster Tissue TMDL Project Imane Mrini Center for Research in Water Resources The University of Texas at Austin

41. Atmospheric deposition Wat = 18.67 kg/d NPS watershed loadings Qwsh = 1.83 m3/s Wwsh = 3.69 kg/d Lake Corpus Christi load QNR = 2.47 m3/s WNR = 4.27 kg/d Nueces Bay Permitted discharges Qpd = 16.55 m3/s Wpd = 0.71 kg/d Mean = 37µg/L CP&L plant WCP&L = 52.75 kg/d Inner Harbor Average Conc. (1982-2001) = 37µg/L Zinc loads to Nueces Bay Q = flow of water W = load of zinc Outflow

42. Physicochemical Reactions sunlight Atmospheric Deposition Photochemical Reactions Inorganic Reactions Flux Flux Organic/Biological Reactions Sediment-Water Exchange

43. Total Zinc in water( ~ 47 mg/L) 0.047 ppm Zinc in sediment( ~ 100 mg/kg)100 ppm Zinc in Oyster tissue(~ 1100 mg/kg) 1100 ppm Bioconcentration of Zinc Ratio = 23,400 Ratio = 2127 Ratio = 11

44. Academic Program at UT • Required courses • CE 319F Elementary Fluid Mechanics • CE 356 Hydraulics • Electives • CE 358 Ocean Engineering • CE 370K Water Chemistry • CE 374K Hydrology • CE 365K Hydraulic Design (Level II)

45. CE Faculty in Water Resources • Randall Charbeneau (groundwater, hydraulic design • Ben Hodges (hydraulics, hydrodynamics) • Lynn Katz (water chemistry) • Spyros Kinnas (fluid mechanics, ocean engineering) • Daene McKinney (water resources planning) • David Maidment (hydrology, geographic information systems)