Lake water systems
 

I was wondering what other people have experienced with this.

I have a good water system that pumps out of the lake all year long.

I decided to install a second, back up, seasonal system for irrigation, car washing, and to feed a second building on the property. They are plumbed so that if either fails I can just open a valve and the remaining one will feed everything.

The intake is about 40 feet from shore, about 2 feet above the lake bottom in about 6 feet of water It is a fairly busy area for boats. It seems to me that the filters get dirty and need to be changed pretty quickly. I am considering extending the intake to 60 feet out in about 10 -12 feet of water. Still 2 feet off the bottom? Maybe.

I am curious where most people pumping from the lake put their intakes or anything they may have learned with years of experience to get the best quality water. If I can't get this a lot better I may consider a well.

You will get much better water quality with drastically less sediment by moving the foot valve out as you suggest. We did the same thing a couple years ago in the same situation, from about 5 feet deep close to shore and moved it out about 75’ to around 12’ of water, and the difference was night and day for our filters.

Mine is right next to the dock in a sandy area so it doesn't pick up any sediment usually.It's only in 2' of water so I don't even need to get wet to check it.

How far off the bottom is your foot valve?

Go deep
 

There are other old threads on this, but the consensus seems to be 10' deep as a minimum. We're only seasonal. We use a well pump underwater, about 18" off the bottom. 10 feet deep at full lake. "Filters? We don't need no stinkin' filters." ( Credit misquote to Cheech Marin) The lab test results give us very high water quality.

Our foot valve is about a foot off the bottom (attached to the top of a concrete block). My sense is that once you get far enough from shore and in deep enough water, the waves don’t churn up sediment on the bottom so it doesn’t need to be too high off the bottom (but you certainly don’t want it too close that pulling the water in creates its own current on the bottom to suck up sediment).

Our valve is on top of a concrete block so about a foot off the bottom. It is about 200 feet out from shore, in about 4 feet of water. We have very shallow depths where we are. We tried to run it about 500' out to get real depth but were having issues getting the line to stay on the bottom so we cut it back (full disclosure, my prop cut it back!).

Many years ago, most systems used galvanized pipe. No problem with floating, but a short life expectancy and some rust issues. Using poly, we thread it through a few concrete blocks. I also thread it through a larger diameter 8 foot section of poly to protect from ice and wave action rubbing on the rocks where the line comes ashore.