MuskogeePhoenix.com, Muskogee, OK

November 21, 2009

Ask Dan: Predicting flooding is tough

By Dan Threlkeld

From C.F.: On average, how much rain would you say it takes before there is flooding?

Answer: There are too many factors to give a specific amount. When very heavy rain falls in a short period, the ground does not have the chance to absorb the moisture, and that creates runoff. If rivers, lakes and creek levels are already high before a storm, then flooding can occur much more rapidly than when basins are lower and the runoff has the opportunity to drain.

Flooding not only causes property damage, it also kills more people every year than tornadoes or lightning. It is second only to the No. 1 weather-related cause of deaths which is heat.

I once read where an area that receives 30 inches of rain per year has an estimated 1 billion drops of rain per square yard! To cover a square acre of land with one foot of water takes about 43,560 gallons of water.

In neighborhoods, keep storm drains clear of leaves and debris that can stop up drainage and lead to street flooding.

Before you move into an ark, check with neighbors and ask about flooding frequency of a street or nearby creek.

Even if you don't live in a flood plain, you could check into the cost of flood insurance.