RE: Is it possible to make your own lake?
Cost being the limiting factor, yes, you can.
I have a settled out sinkhole on the front end of my property that would make a dandy little fishing hole for me and my grandkids, now all I need is a buttload of fill rock and dirt for a berm, truckloads of bentonite clay to line it, about $6,000 to pull it off, and some way to get the heavy equipment in and out. For a 40 acre lake you could select a large low spot or large gully on the property and dam it off, but if the soil perks well you'll need to compact the crap out of the soil and clay line it at least 1-2 feet thick to retain water. Unless you can divert a small creek or spring into it you'll have to wait for rain to fill it, which can take months unless the eveaporation rate exceeds the rainfall. Don't forget that adding a lake to any property will jack up your property taxes too.