Nueces River Flood Briefing Monday May 18 th, 2015

Transcription

1 Nueces River Flood Briefing Monday May 18 th, 2015 National Weather Service Warning Coordination Meteorologist John Metz

2 Overview Multiple Heavy Rain Events this past week have resulted in Major Flooding on the Atascosa River and Nueces River upstream from Lake Corpus Christi. Dangerous Life and Property Threat Along the Nueces River from Near Three Rivers to Lake Corpus Christi, with the river projected to crest approximately 2 feet lower than the Oct 2013 flood. Rapid rises already occurring at Lake Corpus Christi due to rapid runoff from local rains, with a major flood wave arriving from upstream. Lake Corpus Christi is projected to Fill to Capacity and is already at 97% full. Releases from Lake CC will result in Major flooding downstream at Bluntzer and Moderate flooding at Calallen.

3 Rainfall Totals - Last 7 Days 6-8 Choke Canyon Dam Lake Corpus Christi 5-6

4 Areal View of local Rivers & Current Conditions River in Minor Flood Rivers in Major Flood River in Minor Flood

5 Areal View of local Rivers River Creek Acres Subdivision

6 Atascosa River at Whitsett Just Crested Yesterday and now have a good handle on amount of water moving downstream. 3 rd Highest Crest on Record Measured peak flow of 17,000 cfs Gradual Fall During the Week Below Flood Stage Tue Night Impacts: Crops are damaged and pastureland is flooded, cutting off cattle. Secondary roads and low bridges also flood

7 Nueces River Near Tilden Flat Crest Expected next couple days Moderate flooding expected Projecting peak Flow of ~2000 cfs Remaining in Mod/Minor Flood At least through next weekend Impacts: Much of the flood plain below Cotulla to below Tilden is cut off, as sloughs and peripheral channels fill. Hunting cabins, oil field pump jacks and tank batteries flood well away from the channel. Livestock are cut off and can drown

8 Nueces River Near Three Rivers Major Flooding Occurring Crest near 37.2 feet Projecting Peak flow of ~14,000 cfs ~2 feet below 2013 flood Fall below flood stage Late Wed Night Impacts: Widespread lowland flooding occurs. Airport Road boat ramp near Live Oak County Airport is flooded and closed. Major flooding occurs in the River Creek Acres Subdivision, with several feet of water and several homes flooded. Residents in the J.I. Hailey Subdivision at Jones River bend have trouble getting out as water covers much of Antelope Lane.

9 Lake Corpus Christi 96.9% Capacity and releasing 5,000 cfs

10 Lake Corpus Christi is Currently Releasing Peak Flow of 8,000 cfs Nueces River Near Bluntzer Minor Flooding Occurring Based on current releases at Lake CC, the river will rise and reach Major Flooding Today. Long term based on releases from Lake CC. Impacts: Flow cuts off the lowest residential areas downstream above Calallen for days or weeks. Numerous secondary roads and low bridges are under water, from below Bluntzer to below Calallen

11 Lake Corpus Christi is Currently Releasing Peak Flow of 8,000 cfs Nueces River at Calallen River is out of its banks, but below flood stage Based on current releases at Lake CC, the river will reach major flooding. Duration of flood is dependent on releases from Lake CC. Impacts: Moderate lowland flooding occurs. Roads flood through the lowest residential areas, cutting off homes above Calallen, and requiring evacuations. A portion of Labonte Park is under water At 9.5ft. Residents are isolated upstream on the west side of the river ~six weeks.

12 7 Day Rainfall Forecast (Today through May 25, 2015)

13 Impact Summary Dangerous Life and Property Threat Along the Nueces River from Near Three Rivers to Lake Corpus Christi, but cresting 2 feet below Flooding of Homes in Flood Plain Near Three Rivers to Lake Corpus Christi Roads & Bridges Near River Will Flood and are impassable. Residents in the J.I. Hailey Subdivision at Jones River bend have trouble getting out as water covers much of Antelope Lane Lake Corpus Christi releases will impact downstream communities with Moderate to Major flooding. Additional Rains are expected upstream in next 7 days which could impact river forecasts. Last time Nueces river reached 7.5 feet or more at Calallen was Fact - in 2002, Nueces River at Calallen crested at 13 feet cutting off homes for weeks. This was 2nd highest flood of record.

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