The 2017-2018 GRTU Guadalupe River leases are now on sale. They are limited to 750 total leases. There are several changes to the program listed on their site: http://www.grtu.org/
Remember, most of the river banks are private property. If you want access to the better spots on the river, the LAP is really the way to go.
Go to http://www.grtu.org/membership-signup/ to enroll.