State of Texas Hazard Mitigation Plan - Texas Department of Public ...

Sand is also deposited just off shore in sand bars, which after the storm will make its way backonshore and blown landward by the wind. The vegetation on the landward side of the dry beachtraps this windblown sand and rebuilds the dunes for the next storm event.2.2.6 River Basins of TexasAs provided as an excerpt from the 2007 State Water Plan prepared by the Texas WaterDevelopment Board, there are 15 major river basins within the state and eight coastal basins (seeFigure 2-6), each with varying hydrological regimes and localized susceptibility to flooding.Each of the basins has several unique features, both climatic (such as precipitation andevaporation), as well as physiographic (geology, slope, soil type, vegetation and land usepractices) which contribute to the nature of runoff from the basins. Table 2-1 provides asummary of the major river basins and includes watershed area, river length and average flow.Table 2-1: Features of Major River Basins in TexasTotal Area Area in River Length Length in Average FlowRiver Basin (Sq Mi) Texas (Sq Mi) (Miles) Texas (Mi) (Ac Ft/Yr)Brazos 45,573 42,865 840 840 6,074,000Canadian 47,705 12,865 906 213 196,000Colorado 42,318 39,428 865 865 1,904,000Cypress 3,552 2,929 90 75 493,700Guadalupe 5,953 5,953 409 409 1,422,000Lavaca 2,309 2,309 117 117 277,000Neches 9,937 9,937 416 416 4,323,000Nueces 16,700 16,700 315 315 539,700Red 93,450 24,297 1,360 695 3,464,000Rio Grande 182,215 49,387 1,896 889 645,500Sabine 9,756 7,570 360 360 5,864,000San Antonio 4,180 4,180 238 238 562,700- 39 -