I watched the show on the replacement of the upstream gate at John Day Dam.While that is nothing compaired to what is going to happen at The Dalles Dam.In December 2010 the down stream gates (over 100 feet tall and 350 tons each)are going to be removed and new pintle bearings installed,also they will make a cut 11" wide down the entire length fo the gate and weld on new seals.The locks will be completly unwatered a site to see there are just a handfull of people that have seen the locks without water.you will be able to walk in the giant tunnels that are used to fill and drain the locks and see the tainter valves that control the flow.