It would help if we knew where this project is located.

We are trying buffalo grass and Bermuda grass. Now don't die, bur people here are buying up that plastic turf a lot. It looks very real. Personally I would never do it, but a lot of people are.

Seashore Paspalum has been used here in Naples and Marco Island with good sucess! But, no truf grass is without it's problems, as I'm sure you know! Soil ammendments, like the polymer based water absorbing pellets have helped retain some of the irrigation water, but they only last about 5 years. So typical brown patch is a battle as well as web worms & mole cricket problems. As far as water useage comparisons...I've never seen any.

Have you checked out "zoyosa grass" ?