mybe a bit late and a bit lame(reading about greg Webbers design) but after seeing the 'wave garden' shortly b4 a trip to the mountains, in a part of a country with a terrible surfing coastline, with a huge population who travel 100s of clicks to surf regularly, an idea came to me while looking at a gushing 20m wide creek;

use water from a peminent decent size creek to fill a giant water container to drop into a well designed dam to create the wave. capturing all/most of the water after the first dam theres no reason why you couldnt have a whole series of dams down the hill side. an empty water container would be then easy enough to reposition refill and drop again.

i thought it was one of those ideas that are so simple but for some reason unthought of. (still maybe) i dont have the funds or patients for any business dealings to go any deeper but appart from the dam building i cant see a reason why this wouldnt be a goer for a more motivated person.