I was hiking some compost into an area where I have guerilla grown for the past four or five years, when I suddenly noticed that I had been walking right past an endless supply of irrigation water...bright yellow FIRE HYDRANTS. These hydrants are not used for fire fighting, they are instead used to flush the water main once a year.
I realize that fire hydrants are not located everywhere; this is a pretty secluded location where the county installed a very large water main about ten years prior to that. In this case, the fire hydrants are located along the water main, one about every 150 yards. The closest one to my garden turned out to be about 100 ft away.
I do not use the hydrants for watering, I instead use them to top off a 250 gallon, plastic reservoir that I obtained from craigslist. These large, plastic storage containers are used for shipping juice, and other edibles, and can be found on craigslist for anywhere from about $100 up to $250. The tank is stashed in a treeline, adjacent to my garden, with real camo material (expensive) draped over the top of the water tank in order to hide it from prying eyes.
Surplus 1.5 inch fire hose can be obtained on the net for anywhere from $100 to $200 for a 100 to 150 ft piece. I have also seen auctions where they sell large amounts of firehose for next to nothing. Grainger also sells brass adapters that will convert the 2.5 or 1.5 inch output of the fire hydrant to a 3/4 inch garden hose adapter size.
You will also have to obtain a fire hydrant wrench, for turning on the hydrant. When I use this thing to top off my storage tank, I open the hydrant just a crack. I do not want a high pressure stream of water, rather just a garden-hose type flow. It takes about ten minutes to top off the 250 gallon tank. I do all of my other chores while the tank i sfilling, so i am only at the site for ten minutes per visit. Less time if the tank does not have to be topped off. The tank only needs to be refilled once a month; even less if we have sufficient rainfall.
The fire hydrant method can also be used without a holding tank; just soak your garden so well that it will not need to be watered again for a heck of a long time. We are getting into a little extra expense here, but a fire hose nozzle can be purchased for the end of the hose for a little more control of the water flow. See here: Grainger
http://www.grainger.com/Grainger/VIPER-Fire-Hose-Nozzle-4YLK6
Just an idea...I do not know if it will work in your situation. Look around at your area and use what is there, before you haul anything in. At one of my garden sites, there is a truck storage yard with a large pole barn that just happened to have a garden hose spigot installed on the side that I could access from the woods. I used to head out there on a Sunday evening, when I knew that the shop was closed and no one was there. I had 300 ft of garden hose stashed in the bush (again almost free from craigslist). The hose was laid out about once every three weeks (depending upon the weather conditions), hooked to the spigot, and used to thoroughly water the garden. A couple of bags of compost were spread over the top of the garden before watering, so that it is washed into the soil by the irigation water. The hose was then rolled back up and stashed in the bushes, wrapped in heavy canvas for camo and protection.
Just my two cents. I always try to use what is available onsite before hauling anything into the area.
Good Luck
Vinnie Kaz