Friday, June 17, 2011

A Long Dry Week

It's been a long week. We had the post-nephew's-wedding chores, followed by some to-do odds and ends around the house. But what really killed me was the irrigation system at our lake cabin.

It all began last winter, when temperatures up there dropped to single digits for three days in a row. The place is just not equipped to handle low temperatures like that. I had the house pipes wrapped and drained, so we had minimal damage there. But we water the lawn by running a PVC pipe down to the lake and using a pump to draw the water up and pressurize the sprinkler system. There was no way to wrap or drain that pipe, so it burst wide open

I replaced it early this spring. Since then, however, there has been a succession of split fittings in and around the pump house. The only thing I can figure is that they were weakened enough by the freeze so that they burst when under pressure. I finally replaced all the plastic fittings with brass ones, which seems to have solved that problem.

Next, however, the system couldn't maintain a high enough pressure to achieve full coverage. At first I thought it was a leak, but after careful inspection that was ruled out. Turns out the pump has plastic impellers (an impeller is kind of like an internal propeller - it slips over the pump motor's shaft and draws water up from the lake, then boosts it up through the sprinkler system). The threads on the impellers that connect them to the motor shaft were worn, so the impellers weren't spinning as fast as the shaft, resulting in low pressure. I replaced the plastic impellers with brass ones. Success!

Sadly, like many other things in life, success was just temporary. Much of Texas is in the middle of an extreme drought. The eight months from October 2010 through May 2011 have been the driest eight-month period on record for Texas since 1895. Temperatures have also been unseasonably high, averaging about 10 degrees above normal. As a result, 'our' lake (Lake Buchanan) is about 15 feet lower than usual. It's been dropping about half a foot per day over the last couple of weeks. Last week it dropped low enough to expose our input line's foot valve. (The foot valve sits at the end of the pipe in the lake. When the pump kicks on the suction opens the valve and lets water flow into the pipe. When the pump isn't running a spring holds the valve shut, preventing sediment and wildlife from entering the pipe and clogging it up.)

When the foot valve is above water, it can't suck water into the intake line. This causes the pump to run hot, which damages it. So sometime last week a spacer disk in the pump burned out, leaving the lawn without water for the nth time this year.

So this week was occupied with replacing the burned out spacer and extending the intake line another 100 feet into the lake. Where we are on the lake the bottom slopes so gradually that going out 100 feet horizontally only gets about an eight foot vertical drop. That means that if the lake keeps going down at the same rate the foot valve will be exposed again in about two weeks.

Bottom line - the lawn is the color and texture of straw. The landscaping, such as it is (a couple of rosemary bushes and crepe myrtles) is dry and shriveled, but just barely holding on. Fortunately the grass is zoysia, which just goes dormant when it doesn't get enough moisture. A little water will perk it right up.

We desperately need rain down here. A nice tropical depression floating up from the Gulf and hovering over Central Texas would be very welcome about now...

1 comment:

kerrcarto said...

I wouldn't mind a Katrina type hurricane coming up and hitting Corpus. At least we would get some MUCH needed rain.