Widespread rain event needed to fill Lake Granbury

What will it take to fill Lake Granbury?

Not the couple of inches here early this week. Five inches of “intense” rain over a wide area upstream might do the trick.

Many things, however, factor into the water equation to fill the lake, according to Water Services Manager Brad Brunett of the Brazos River Authority (BRA).

nWhere the rain falls.

nHow large of an area it covers.

nHow fast it falls.

nHow much soaks into the ground.

nHow much gets captured in upstream lakes and ponds that are also low.

Brunett explained that the watershed area above Lake Granbury is a big factor in refilling the drought-weary lakes.

“The drainage area upstream that produces runoff to Lake Granbury covers about 16,000 square miles and extends west to the area around Lubbock,” he said.

“Five inches of intense rain over this entire area in a short period of time would produce enough runoff to completely refill the lake from empty many times over.

“However, if the five inches of rain is spread out over an extended period of time – say several weeks – there would be little runoff that would make it to the reservoir due to the exceptional drought conditions we are experiencing.”