Well pressure

I am having what seems to be a well pressure problem. It is ONLY evident when the lawn sprinklers are on, so far. When any zone is watering, the pressure starts out good, then gradually drops to a trickle. This will occur even when no other water is running. The pressure switch cuts on and off correctly. Seems all in house systems are working correctly but we never run water in house as much as the sprinklers. I do have a Pumptec installed. (Thank God) I believe if the pump screen were clogged, the low pressure would be evident immediately. If the pump were gradually weakening, wouldn't the Pumptec cut it off? How long will a pump run dry before Pumptec cuts it off? OK, maybe the well is OK and I am jumping the gun. Hopefully it's the sprinkler system. Can a sprinkler pressure regulator cause this? Or maybe a big leak that the pump can't keep up with?

PS. We are in Austin Texas and we are in an exceptional drought. I am in the Trinity aquifer if that helps. Have no idea what my static level is.

Thanks for any help.

Sounds to me like you are drawing down the well faster than it is recovering.
The well is producing water, just not enough. The lower the water level in the well the harder it is for the pump to push the water out of the well, hence you get a gradual pressure drop. Eventually you get to a point where you are just pumping out whatever the well is producing.

A partially clogged screen would make this problem appear earlier in the well draw down as the pump will have to work harder causing a pressure drop. I have a low yield well I use for irrigation (2gpm - 400 feet deep - static water level 6 feet from the top). I know how long it takes to draw down the well and program the timer to water only a few zones at a time.

If you are using a low yield well for irrigation you really need to find out everything you can about it to determine IF you can use it for such a purpose and how to program your zones to get the most out of it without killing your pump.

-rick
-rick

Rick - do you have a holding tank or just using the storage in the well plus a bladder?

Austin

This link has some pretty pessimistic news

"Unlike the Edwards, the Trinity Aquifer recharges very slowly. Only 4-5% of water that falls as rain over the area ends up recharging the Aquifer, and water also moves through the Trinity much more slowly than through the Edwards."
http://www.edwardsaquifer.net/trinity.html

"Mean Annual Precipitation: 31.9 inches" so I guess you're way below this figure for this year. . .

Pandela said:

Very interesting link. Thanks!!

Click to expand...

In principle, if you can put all the numbers together, along with predictions, past rainfall history, etc., you could calc. the necessary size of a holding tank to get you through droughts.
Or somebody's computer could. And that computer probably belongs to the consultants hired by all these counties in TX.
They read and understand books like this
http://books.google.com/books?id=62...763oCA&sa=X&oi=book_result&ct=result&resnum=2

BTW, I don't guess you remember that sniper in the Univ. of TX tower at Austin? I was in San Antonio at the time, as a guest of the USAF. They made a movie about it, eventually.