Here are the facts as I know them.

1  Have a field with a normal main irrigation pump bring water up out of the ground.  This pump feeds water into and underground pipe for the field. The field is watered with gated pipe. 

2  We also have a reuse water pit located in one corner of the field.  It catches the run off and recycles the water.

3  We believe, through our test, that no water from the reuse pit is getting to the main under ground line. It is an underground line from the reuse pit to the main line.  ( I took a cap off the main line so I could see the bottom of the line.   We started only the reuse pit pump and no water would come into the main line after 1 hr. running.)

4  Had the well company come out and check the reuse pit pump.  Pump is putting out 450 gpm.  It is not the pump, nor a plugged feed line to the reuse pit pump.

5  With the main line running I am way short of my normal water supply.  I have about 60 to 75% of normal I think.

6  So you would think we have an underground water line leak from the reuse pit to the main line. Right?

7  If that was true the underground leak would come to the surface and run out the end of the field.  You could walk back up the corn rows and see it bubbling out of the ground.  Yes?

8  Here is the problem.  We find no water running out the end of the field and no bubbling back up out of the ground. 

9  Now here is what I think after all this head scratching.  I think the pipe is broken or cracked by the reuse pit underwater were we can not see the water coming back out of the pipe.  We are just pumping the water 10 or 50 ft around  in a circle. 

11  Man this is getting long.  I think if I could empty this pit by stop pumping with the main pump of course,  and unhook the underground reuse pipe from the reuse pump and use the reuse pit pump to pump the water over the hill so it does not run back into the pit.  When the water is quite low.  Do not want it to low or the pit pump will not pump.  But when it is low re hook up the pit pump pipe to the under ground pipe and see we if we can not see the water coming back into the pit when the reuse pit pump is on. 

Am I crazy ?  Did any of this make any sense to you at all ?  With out solving this problem my pump capacity is 1/2 normal and it is 6 to 7 weeks before we are done pumping. 

TIA