Floodplain management in the Las Vegas Valley

ABSTRACT

The Las Vegas valley and Clark County have a long history of flooding and flood damage. The Las Vegas valley is unique in that it is surrounded by mountain ranges with steep slopes that empty onto alluvial surfaces. Ultimately stormwater runoff has to pass through areas that are being rapidly urbanized. The steep slopes and unpredictable flow paths on the alluvial fan surfaces compound the flooding and engineering problems facing developers and the Clark County Regional Flood Control District. The problems also include the possibility of flood waters transporting tremendous amounts of debris and sediment. In the urbanized areas of the Las Vegas valley, development and pavement of the desert increases direct runoff and speeds its flow. It is difficult to convince newcomers that the threat of severe flooding exists in a desert region that receives only 4 inches of rain annually. More recently, since the 1960s, the Las Vegas valley has experienced unprecedented, rapid growth