Close this window. The 1984 National Minimum Drinking Age Act, [23 U.S.C. Â§ 158], requires that States prohibit persons under 21 years of age from purchasing or publicly possessing alcoholic beverages as a condition of receiving State highway funds.
Desert soil is thin and dry and cannot absorb a sudden rainstorm and there are few plants to absorb water. The rain rushes down hillsides and mountains and overflows arroyos, flowing into roads and homes in its path. They can occur suddenly and areas far from the actual storm can be flooded.esert soil is thin and dry and cannot absorb a sudden rainstorm and there are few plants to absorb water. The rain rushes down hillsides and mountains and overflows arroyos, flowing into roads and homes in its path. They can occur suddenly and areas far from the actual storm can be flooded.
One cause of floods can be forecast months in advance--snow. Sometimes the ground is too hard or too wet to soak up water. The only place the rain can go is downstream. Usually rainfall of more than one inch in one hour is needed to cause a flash flood. Sometimes a place can get hit by a flash flood even if it's sunny because it might be raining on higher ground somewhere. The floods in Poland this summer weren't flash floods. They were caused by heavy rainfall but the rain was spread out over days. So much rain fell that the rivers couldn't handle all the water.