Are you interested in getting almost free water? If so, maybe catching rainwater from your roof is something to think about. I found that a 50 gallon trash barrel will fill up surprisingly fast with only a small or medium sized rain. Even a light rain can fill up a five gallon bucket in no time.
Mosquitos? No problem. Mosquito fish will take care of the problem easily. Just think about how much water comes from the roofs of government buildings, schools, businesses, roads, streets and highways. This water can be easily purified with water hyacinths, a beautiful, orchid-like aquatic plant.