David, your photos are lovely. What you are seeing is mostly a reflection of the development in Sacramento. The places where the water could have soaked into the ground are now covered with pavement and houses. It flows into the drains and dumps directly into the river. The upstream dams are letting some water through, but most of it is being held for future use. The interesting part of all of this is that we are concerned about building the levees higher and wider while the silting continues to build up the bottom and development continues to add water to the river. Perhaps another view of the problem is in order.... Your wonderful photos are a beautiful place to start in starting that discussion.