Finding a small leak

[bobw]

Anyone got any ideas on how to find a leak on a lateral line? To be honest, I'm not even sure that there is a leak; could just be a ground water issue...but I guess I need to try and sort it out.

The scenario is a large turf berm. There are three laterals on it (north edge, middle and south edge), heads are RB 6504s. Near one end of the berm, we've observed a good amount of water pooling in tree wells; enough so that several trees have drowned.

The system is all run on battery op controllers (no AC power on site) and we're working off of 2 1/2" lines stepped down in size as needed.

There is no obvious sign of a leak; just the pooled water. Nearby homes do have sump pumps in their basements, so there is some reason to believe that the water table is high enough that this could just be ground water. However, this has only started happening the last couple of seasons.

Last year, I shut down the middle line for a few weeks and the water seemed to dissipate; I turned it back on and turned the north line off and the water seemed to dissipate. Even with both lines cut to half of their watering time, the water issue seems to return.

I'd like to get this site sorted out before the season begins in earnest; its over an hour travel time each way to the site, so even the simplest repair is very time consuming.

Anyone have some thoughts as to next steps?

edit to add: My basic assumption right now is that there is a frost crack on the PVC and the ground is getting saturated when the zone is running and then the line is draining out through the crack. Laterals are about 450' long.

[JeffY]

Does the water immediately start pooling up when you check it or is it after several days? You said you cut the watering times in half for both zones, but what about your watering days as well? Since shutting off one and then the other seems to eliminate the water pooling, I feel its too many watering days that doesn't allow the soil to dry out.

[bobw]

Does the water immediately start pooling up when you check it or is it after several days? You said you cut the watering times in half for both zones, but what about your watering days as well? Since shutting off one and then the other seems to eliminate the water pooling, I feel its too many watering days that doesn't allow the soil to dry out.

It takes several days for the water to build back up.

It's pretty easy to guess that its too much watering, but how would you explain that the same amount of water wasn't a problem three years ago?

Also.. as the laterals are 450' long, turning down the watering for one zone too much will allow the unaffected 400' to get too dry.

[DanaMac]

Could it be the valves are seeping?

Cap off the sprinkler heads, turn on the zones, and see if water comes up anywhere.

Ground water levels can change over time.

You say that you turned off some zones for a while and it dissipated. Then it started again after it was turned back on. It could just be that there is too much water with the sprinklers and ground water combined. How many days are you watering? be honest. Don't tell us what it SHOULD be watering or what we want to hear for good watering practices. It could be just too many days and too long of run times.

[bobw]

Could it be the valves are seeping?

Cap off the sprinkler heads, turn on the zones, and see if water comes up anywhere.

Ground water levels can change over time.

You say that you turned off some zones for a while and it dissipated. Then it started again after it was turned back on. It could just be that there is too much water with the sprinklers and ground water combined. How many days are you watering? be honest. Don't tell us what it SHOULD be watering or what we want to hear for good watering practices. It could be just too many days and too long of run times.

I don't believe the valves are seeping. No movement on the water meter.

The battery op controllers (crappy RB ones..) run every 3rd day. 15 minutes on the north line and 30 on the middle. Heads are 6504 with beige (#12) nozzles. 55 PSI static pressure (comes off 4" source).

edit to add: Turf grass here requires 1"/week. Site is full sun.

[Wet_Boots]

Run the zones with the heads shut off.

[FIMCO-MEISTER]

The only way to really do it is as WB and Dana said. Cap off all the heads.

[WalkGood]

If you have a large high volume air compressor (tow-behind type), you *could* blow air through the line with the heads capped off. Start listening to the ground around the swampy area. From 450' away, you won't hear the compressor very loud.

[GreenerGrass9]

It also could be the battery valves are coming on when they are not suppose to and you don't know it. I've had that problem before. What happens is the batteries get weak in voltage so the magnet in the solenoid actavates for a few minutes when you are not there and you never know it.

[AI Inc]

The only way to really do it is as WB and Dana said. Cap off all the heads.

If they are pgp,s , you can get 0 nozzles on a low angle nozzle rack. Easy way to cap.

[unit28]

ground is frozen..Canada right?
your run times are a determing factor along with nozzle size and head placement.

Cap the heads as was noted and run it.
which is it..sun/shade?

you said tree wells, so I'm asking, did you bump the times up, splitting the difference so it will run more than once per day to keep the sunny side from drying out?....

"we've observed a good amount of water pooling in tree wells; enough so that several trees have drowned."

[unit28]

you may want to wait to kick that system on...LOL
I know you are just asking for the next steps, but winter is over right?...sheesh


FPCN15 CWWG 142130
Forecasts for southern Alberta and the Mountain Parks issued by
Environment Canada at 4.00 PM MDT Tuesday 14 April 2009 for tonight
Wednesday and Wednesday night.
The next scheduled forecast will be issued at 5.00 AM Wednesday.

City of Calgary.
Tonight..A few flurries ending early this evening then clearing. Wind
north 40 km/h gusting to 60 becoming light this evening. Low minus 5.
Wednesday..Sunny with cloudy periods. High 7. UV index 4 or moderate.
Wednesday night..Clear. Low minus 5.

[bobw]

you may want to wait to kick that system on...LOL
I know you are just asking for the next steps, but winter is over right?...sheesh


FPCN15 CWWG 142130
Forecasts for southern Alberta and the Mountain Parks issued by
Environment Canada at 4.00 PM MDT Tuesday 14 April 2009 for tonight
Wednesday and Wednesday night.
The next scheduled forecast will be issued at 5.00 AM Wednesday.

City of Calgary.
Tonight..A few flurries ending early this evening then clearing. Wind
north 40 km/h gusting to 60 becoming light this evening. Low minus 5.
Wednesday..Sunny with cloudy periods. High 7. UV index 4 or moderate.
Wednesday night..Clear. Low minus 5.

Trust me.. I am VERY aware of the weather here. lol

I'm just plotting a strategy for that site right now. Some time in the next week or so, I need to call the property management company and give them some idea of what kind of costs they are looking at.

The real challenging part of this repair (if there is a leak...) will be locating the leak itself. Its not like we have water gushing up or even a soft spot in the area affected. I really don't want to rip up 100' of turf and hand dig to try and locate a leak. Even at a decent hourly rate, its just not the type of work that makes me happy.

[Wet_Boots]

If you cap the heads, a leak will show itself.

[FIMCO-MEISTER]

If you cap the heads, a leak will show itself.

I agree Boots.