Testing yard strip drain

Background: I have about 300 ft of strip drain I installed several yrs ago in backyard to carry off downspout water and help drain the swale area of my yard where water would stand for weeks in the winter after any significant rain.

Today: I want to test the flow of this drain as I have never seen any water flowing from the emitter at the end of the line. I can see water in the drain by raising the cap. I'm wondering if I could gently pressurize the drain at the upper collection basin/input into drain with my air compressor. I'm thinking initially any water in system would expel from emitter then there should be a steady rush of air from emitter if there is no blockage in the system? Anyone have any experience doing this or know another way to effectively test the system?

 

You have 300' of collection drain pipe..... so you can't pressurize that.

If your system had a water flow issue you would have water backing up at the collection grate.
Is that happening ? If not.... why worry ?

 

First, what is a "strip drain".

It sounds like you have a pop-up emitter or outlet at the discharge end. Keep in mind that water flows downhill. For the emitter to work the water in the pipe must be above the top rim of your emitter. What I often see is a long run of perforated drain pipe then a 90 degree fitting going vertical to a grill or emitter. What people often forget is that the water will not magically rise up and out the emitter. It's especially an issue where there is not much fall/elevation change and even when there is decent elevation the low part of the pipe never drains and tends to collect debris and clog.

I don't think pressurizing your drain will work. It's a drain so it's probably full of holes to let water in. So, when you pressurize the air will take the path of least resistance out which is probably through the drain holes along it's length and not the emitter way at the end. The best way to test probably would be to put a garden hose in the drain pipe at the top end. This would work best if you did it right after a heavy rain when the ground is saturated. That way the water you put in has less chance of escaping out the drain holes and not through the emitter at the end.

 

During a heavy rain, the mid stream basin will overflow sending more water into my swale area. It's frustrating that I was careful to route the drain through the area where the water tends to collect and used a very coarse construction grade sand to allow standing water to perk down into the system.

The slope is gentle, but the end is definitely lower than the collection points. Here's a linky that describes the strip drain system. I got it at Lowe's.

http://cadeco.com/productfiles/Ameri...StripDrain.pdf

 

I wonder if I just eliminated the 2 collection basins and routed the 2 downspouts straight into the strip drain, maybe the head pressure would be great enough to move more water all the way to the end and out the emitter?

Before I got the system, in the engineer's notes, he said the strip drain relied more on the principle of displacement rather than a certain minimum slope to move water.

 

If you installed the strip on flat ground starting at grade and ran a trench slope of 1 inch/10 ft. you would have a terminal trench depth of 36 inches (assuming you used 6 inch strip). For your strip to be successful, the ground must have a constant slope of 36 inches in 300 feet. The bottom of the strip should exit exit at grade. Another possible problem is the backfill has compressed the strip so there is very little space for water to flow. How did you determine the compression strength of strip to use?

 

There was only one option(type) strip drain at Lowe's to get so.............I have to assume( shudder) that it is the proper material for a typical home lawn drain application. I knew going into project I would not probably have 1 inch drop per 10 ft so that was another attractive thing abt the strip, their claim that the drop is not as significant as with a traditional 4" pipe.

Another possible help to the system might be changing the tee connection I have at the lower part of yard for a more gentle wye type connection, maybe the water would flow better? Now, the water coming from the downspouts and whatever if anything is being collected from the swale area has to make a hard right turn to go another 25 feet to the exit.

 

Just because the manufacturer says its so doesn't mean its true. If they had said their strip makes water flow uphill, would you have purchased it? If there is no area on your property below the grade of the trouble area, you might consider installing a drywell in the trouble area and have the strip drains terminate at the drywell. Hope this helps.