Lake for a water supply.

Discussion in 'Irrigation' started by bmyownboss2005, Jun 29, 2005.

  1. bmyownboss2005

    bmyownboss2005 LawnSite Member
    from Saxe VA
    Posts: 30

    Hello all. I am considering installing an Irrigation system and I need a little advice. Behind my house I have a 30 acre private lake that I would like to use as my water supply. It's about 100 to 150 yards away and down a pretty steep hill. Would it be economical to use that or simply use my well water for my source? I realize I would have to get some type of pump and it may have to be a pretty stout pump to accommodate the suction lift. I also thought about using a head tank with a booster pump. Has anyone ever tried or seen anything like this.
    Thanks in advance.
    Harvey :)
     
  2. Dirty Water

    Dirty Water LawnSite Fanatic
    Posts: 6,799

    It really depends on what is more cost effiecent. Pumping from the lake is already at a disadvantage because your own a well, so your not going to save any money on the water bill.

    If you get awesome PSI and GPM from your well, I'd just go off that. If its rather unimpressive, I'd look into going off your lake, but you would have to buy a pump, pressure tank, and then have to replace a spin-down filter every so often.

    Theres also the hidden cost of having a utility contractor running 220 out to the pump location.
     
  3. bmyownboss2005

    bmyownboss2005 LawnSite Member
    from Saxe VA
    Posts: 30

    Thanks for the speedy reply. I am not really looking into saving money on my water bill, but concerned about running the well dry during the really hot seasons. I have approx 3-4 acres to water and my soil is a dry sandy type and in other areas it the red clay type. It is a new yard and I am going nuts trying to keep it watered. We haven't had much rain lately so my lawn is brown. It is a young lawn and is not very well deep rooted and I am concerned about it dying . My house is a new construction and I believe I have about 50 or better psi on my well. As far as hiring a utility contractor to run 220 I can do this my self. I have a trencher I can use at any time. What size pump would you recommend? What about the piping? I know you might need more specifics but I am just tooling around with the idea for now.
     
  4. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,003

    I wouldn't go nuts about rescuing a young lawn that can always be reseeded. You have the acreage needed to make this worth pursuing. What you have to know to the foot is the elevation profile of the property. In general, a pump has an easier time pushing water than pulling it. With flat property, a standard (non-jet) one horsepower utility pump could pump all the water you'd want (40 gpm) but at a low pressure, that you would have to preserve by using larger pipe diameters and valve sizes, and by using sprinkler heads that can perform with less than 30 psi. That costs money to install, but less money to run, so there is a long-term payback.

    If the water has to be pumped up a hill, you need a jet pump, or even a multi-stage jet pump, which will take more horsepower to push less water at higher pressures. Most such units will pump around 20 gpm, depending on elevations and horsepower, which can handle the acreage. Larger than that will be hard to find. Take the high-pressure route, and you gain some economy in the sprinkler system, as heads will spray farther, and can be spaced farther apart.
     
  5. Leo's

    Leo's LawnSite Member
    Posts: 21

    i personally love lake water for watering its free nutrients automatically from the lake, but anyway i suggest using a sta-rite berkely pump. Depending on how big the hill is and how many heads per zone you want to run I wouldn't use anything less than a 2hp dual stage pump, but if money isn't a problem and you want to pump some serious water get a 5hp pump, with a 2 inch mainline. Also up here in Michigan no one really uses a pressure tank for the lake pump, I have seen it maybe 2 times in 10 years, and they didn't work very well. Just my 2 cents
     
  6. GreenMonster

    GreenMonster LawnSite Silver Member
    from NH
    Posts: 2,702

    I have a set-up similar to what you are talking about. Well pump attached to my dock, pumps a rise of about 60' and a run of about...mmmm..... 200' maybe, with a pressure tank set-up up at the top. I'm getting ready to finally run automated irrigation off it. Sorry I can't give you any more on the pump specs, I don't know what they are. I just called a pump outfit and had them do the install. Only thing I did was the grunt work -- burying the line :cry:
     
  7. jerryrwm

    jerryrwm LawnSite Bronze Member
    Posts: 1,274

    Designing irrigation systems with pumps is just bass-ackwards from a water meter system. With a water meter you are restricted to the capacity of the meter/service. With a pump system you determine the requirements of the system - pressure and flow, and then find a pump that will deliver them. The only real restriction is the depth of the pocket. You could put in a verticle shaft turbine pump that would water the hell out of the area, but you can spend some serious coin.

    You have two options that you could use for pumping out of the lake.

    1. A centrifugal pump set on a pad no higher than 20' above the static lake level. You will need to know the elevation that the pump will need to overcome to get the water to the highest point at the proper pressure. Calculate the pressure requirement at .433 psi for every foot of elevation, plus friction loss in the mainline, plus required system pressure at designed flow rate. This will determine the size of pump required. One example is a Monarch pump 5 hp that will deliver 30 GPM at 73 psi. at 5' of suction lift. If you are designing rotor heads at 45 psi, you have 28 psi available for loss due to friction and elevation. Loss in 2" mainline (SDR-21) is 0.6 psi/C' is about 4.0 psi. Now you are at 24 psi available. For sake of argument let's use 5.0 psi loss for valve and lateral losses. You are at 19 psi available now. So that will dictate that the elevation change from pump to highest elevation can be no more than about 40'.

    2. A submersible pump installed in a shuck and on a stand. All the above factors pertaining to elevation changes and friction losses must still be taken into consideration.

    Once you have a design of the irrigation system, get with a pump expert to help you size the pump. They have the pump performance curves and can get you the correct pump.

    Hope this helps.

    Jerry R
     
  8. Dirty Water

    Dirty Water LawnSite Fanatic
    Posts: 6,799

    Does everyone just use pump start relays off the controller there? We typically use a pressure switch, so that we can add hydrants to the system as well.

    If you have your GPM balanced, you wont cycle the pump without a pressure tank, but its a nice safety buffer, and a must if you have any hydrants on it.
     
  9. bicmudpuppy

    bicmudpuppy LawnSite Silver Member
    Posts: 2,781

    UNLESS it's a very small gpm output pump, you MUST have a pressure tank to run a hydrant/hose bib, BUT I still use an electic valve for the hydrant and let the clock call for water. Also, a pressure switch is a must if nothing more than a fail safe so you don't run the pump w/o flow. Pumps that cavitate do not last long.
     

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