www.lcra.org
LCRA’sLCRA’s HydrometHydromet SystemSystem andand ItsIts UseUse inin FloodFlood SituationsSituations
BobBob Rose,Rose, MeteorologistMeteorologist LowerLower ColoradoColorado RiverRiver AuthorityAuthority Austin,Austin, TexasTexas TheThe ColoradoColorado RiverRiver BasinBasin www.lcra.org TheThe LowerLower ColoradoColorado RiverRiver BasinBasin www.lcra.org
The Basin is Roughly 18,300 Square Miles HistoricalHistorical HeavyHeavy RainRain EventsEvents www.lcra.org
Colorado River July 2002 45” Basin HighlandHighlandHighland LakeLakeLake DamsDamsDams www.lcra.org
Lake Buchanan Buchanan Dam
Inks Lake Starcke Dam Lake LBJ Mansfield Lake Travis Lake Dam Marble Falls Inks Dam
Lake Austin
Wirtz Dam Tom Miller Dam Radar-RainfallRadar-Rainfall EstimatesEstimates areare notnot www.lcra.org AlwaysAlways ReliableReliable www.lcra.org
Because of the limitations of radar/rainfall estimates and the short travel times between the tributaries and the Highland Lakes, LCRA made the decision to build a dense network of automated gauges across the Lower Colorado River Basin to assist with flood forecasting and flood warning. LCRA’sLCRA’s HydrometHydromet SystemSystem www.lcra.org • 162 rainfall/temp/humidity gauges • 70 stream flow gauges • 16 lake level gauges • 6 primary lake gauges • 6 acoustic velocity canal gauges • 2 bay gauges • A total of 262 gauges stretching from near Abilene to Matagorda Bay. OklahomaOklahoma MesonetMesonet www.lcra.org
120 Weather Monitoring Locations TypicalTypical Streamflow/WeatherStreamflow/Weather CollectionCollection www.lcra.org WeatherWeather CollectionCollection SiteSite www.lcra.org www.lcra.org http://hydromet.lcra.orghttp://hydromet.lcra.org www.lcra.org GaugesGauges areare MostMost DenseDense NearNear thethe www.lcra.org LakesLakes StreamStream GaugeGauge DataData isis ColorColor CodedCoded forfor www.lcra.org BankBank FullFull andand FloodFlood StageStage RainfallRainfall andand TemperatureTemperature DataData isis ColorColor www.lcra.org CodedCoded forfor EaseEase ofof ReferenceReference TemperatureTemperature DataData www.lcra.org LCRALCRA “Legacy”“Legacy” RainRain SummarySummary www.lcra.org HydrometHydromet PagePage www.lcra.org SituationSituation ReportReport www.lcra.org SituationSituation ReportReport www.lcra.org LCRALCRA RiverRiver ReportReport www.lcra.org Bob’sBob’s WrittenWritten andand VideoVideo BlogsBlogs www.lcra.org DataData isis SharedShared withwith PartnersPartners andand www.lcra.org OutsideOutside AgenciesAgencies • Army Corps of Engineers –Fort Worth • Army Corps of Engineers Hydrologic Engineering Center (HEC) • National Weather Service, WGRFC • USGS CWMSCWMS CorpsCorps WaterWater ManagementManagement SystemSystem www.lcra.org
National Weather Service CWMS Data Data SERVER Observed Collection Base Data
Data Processing Public and Data Storage Cooperators Modeling
Modeling Data Information Visualization dissemination Instructions
River Operations Center
Water Control Management Decision Process (Adapted from Fritz, et al., 2002) GeneralGeneral StepsSteps toto FloodFlood ForecastForecast www.lcra.org Rainfall MFP (part of HMS) Hyetograph
Hydrologic Model HFP (part of HMS)
Hydrograph
Reservoir Operations Model (ResSim) Hydraulic Model (HEC-RAS) ReviewReview ofof CWMSCWMS atat LCRALCRA www.lcra.org
INPUT TO CWMS NWS – MPE(radar only, gage adj.) WDT – QPESUMS NWS Forecasts Gage only NWS QPF’s NWSNWS MPEMPE ViewerViewer www.lcra.org QPESUMSQPESUMS www.lcra.org LocalLocal GaugeGauge CorrectedCorrected ProductProduct (LGC(LGC))
dist _ stn w exp mosaic KAPPA dist_stn= distance from grid cell to gauge
large KAPPA (like Average-smooth)
small KAPPA (like nearest neighbour-blocky) NextNext GenerationGeneration ofof MPEMPE (Q2)(Q2) www.lcra.org LessonsLessons LearnedLearned –– AugustAugust 20052005 www.lcra.org
Two Different WDT Inputs to CWMS
Impact on Forecasts vs. Observed Stream Response Radar Local Gage Observed Peak Flow (cfs) 22,808 12,805 12,051 Volume (acre-ft) 134,213 89,475 79,056 LCRALCRA CWMSCWMS -- 20072007 www.lcra.org LakeLake TravisTravis -- ForecastForecast www.lcra.org
Observed Daily Lake Level Daily Elevations of Lake Travis Full - (Elevation 681) 1996-present2007 710
700
690
680
670 Elevation (msl)
660
650
640 1/1/2007 3/1/2007 4/29/2007 6/27/2007 8/25/2007 10/23/2007 12/21/2007 Date RainRain gagegage ValueValue –– MarchMarch 20072007 www.lcra.org RADAR ONLY RADAR - Local bias gauge adjustment
No gates 2.5 gates-Wirtz 8.5 gates - Starcke RainRain GageGage ValueValue –– FlashFlash FloodsFloods www.lcra.org
Sandy Creek near Kingsland Observed Flow Sandy Creek at Kingsland Observed Flow Sandy Creek near Click March 30, 2007 Observed Flow Sandy Creek near Willow City Observed Rainfall at Kingsland 16000 Observed Rainfall at Click 0 Observed Rainfall at Willow City 2 14000
4 12000 6
10000 8
8000 10 Flow Cfs Flow 12 6000
14 Cumlative Rainfall in inches 4000 16
2000 18
0 20 3/29/2007 3/30/2007 3/30/2007 3/31/2007 3/31/2007 4/1/2007 4/1/2007 4/2/2007 4/2/2007 12:00 0:00 12:00 0:00 12:00 0:00 12:00 0:00 12:00 Date ForecastForecast BenchmarkingBenchmarking www.lcra.org
Overall - Lake Travis Forecast Average Difference(Forecasted - Observed) in ft 12 hr 24 hr 48 hr March 12 to 14, 2007 -0.1 -0.1 -0.5 March 27 to 31, 2007 -0.2 0.1 0.25 May 27 to 30, 2007 0.01 0.18 0.21 August 16 to 17, 2007 0.1 0.57 1.06 Larger Event June/July 2007 -0.1 -0.23 -0.86 ForecastForecast BenchmarkingBenchmarking www.lcra.org
6/27/2007 3:00 am the 12 forecast was under 1.5 ft 6/27/2007 6:00 am the 12 hour forecast was 0.05 ft under 24 hour forecast was 1 ft under 48 hour forecast was 2.5 ft under
By 6/27/2007 2:00 am we had our first forecast for 4 gates It was confirmed by 3:00 am and gates opened at 4:45 am
The peak/plateau wasMarvle Falls predicted 6 ENE Rainfall 24 hrs ahead 20
18
16
14
12
10
8 RainfallInches in
6
4
2
0 6/26/2007 21:00 6/27/2007 0:00 6/27/2007 3:00 6/27/2007 6:00 6/27/2007 9:00 6/27/2007 12:00 ForecastForecast BenchmarkingBenchmarking www.lcra.org • Models were calibrated against 1997 June 2007 June 1997 Peak Lake Elevation 701.5 705 Peak Inflow into Travis 250, 000 cfs 300,000 cfs Elevation at start of Flood 681 681 Period of Time 51 days 46 days
LCRA Corporate Archives #: W000734 NewNew OfficeOffice BuildingBuilding www.lcra.org NewNew OfficeOffice BuildingBuilding www.lcra.org NewNew OfficeOffice BuildingBuilding www.lcra.org NewNew OfficeOffice BuildingBuilding www.lcra.org NewNew RiverRiver OperationsOperations CenterCenter www.lcra.org www.lcra.org
BobBob Rose,Rose, Meteorologist,Meteorologist, LowerLower ColoradoColorado RiverRiver AuthorityAuthority 512-473-3350512-473-3350 [email protected]@lcra.org