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low water pressure after doing repairs

Hello all,
Here is the delemma. While digging a trench I caught and ponctured the 1" water main. The leak was fixed but when I turn the meter back on, the water pressure is good for the first 8-10 seconds than it drasticly is reduce. I figure that some debris infiltrated the pipe and is plugging it. Now what should be my next move? I thought about cutting the area I had repaired , flush the main to make sure it is not in that section ( the water line is about 600' and the repair happened 500' from the meter). If that is clear, how do I procede to flush the water out from the house to clear that last section. I was thinking to run a hose from my nearest neighbors outside faucet ( three hundred feet away) plug it into my back faucet and try to flush it that way. But will that be anough pressure to clear the debris, 150' some 20' going up hill? Any ideas or suggestions from similar experience would be appreciate. Thank you

Re: low water pressure after doing repairs

What type and size pipe do you have? If it's galvanized pipe you may not be able to clear it.
What may work is to flush it back towards the meter with compressed air. Of course to do that you have to disconnect the line from the meter.


Re: low water pressure after doing repairs

Where is this lack of pressure showing up?

If it is at the faucets, remove the screens at the faucet and clean them. If still slow, remove the hoses below the faucets one at a time and flush them. While you have the cold hose off, turn the hot water on at the faucet to flush out the faucet. Reverse the process for the hot side.

If you have a slow filling toilet, you'll be taking the toilet filler apart to get at the teensy diaphram and clean that. You may find it a good time to replace the whole filler mechanism.

If its slow at the clothes washer, remove the screen at the washer end of the filler hoses.

Don't forget to flush out your hot water tank.

You shouldn't have any problems with your tub, but the shower has a screen / flow restrictor at the head. Remove and clean. The head itself may be clogged too.

Re: low water pressure after doing repairs

My 2 cents:

For a fast line clearing do what Houston suggests, because chances are that there is dirt, tiny rocks and other things in more than one faucet. You will need to clean ALL angle stops, supply lines and faucets. If you have a pressure regulator, it must be cleaned too.

If you still have low pressure, you may have blockages in the pipes. That's a different issue. And if your pipes are galvanized, consider replacing them.

Re: low water pressure after doing repairs

Thanks for the input, the pipes are cooper as the house is ten years old. When I first turn on the water after the repair was done I turned the front outside hose on to flush any dirt out, that is went the pressure issue was obvious. Thanks again

Re: low water pressure after doing repairs

Chances are any debris that entered the main line to the house would be caught at the meter and /or a PRV. If it's in the meter then you have to call the water utility to replace it --- the PRV generally has a filter/strainer that may be cleaned out , otherwise, and depending if it can be disassembled the PRV may need replacing

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