River delta slope offshore, waves will make river deltas smoother. Waves can also be responsible for carrying sediments away from the river delta, causing the delta to retreat. For deltas that form further upriver in an estuary, there are complex yet quantifiable linkages between winds, tides, river discharge, and delta water levels. Erosion is also an important control in tide-dominated deltas, such as the Ganges Delta, which may be mainly submarine, with prominent sandbars and ridges. This tends to produce a "dendritic" structure. Tidal deltas behave differently from a river- and wave-dominated deltas, which tend to have a few main distributaries. Once
Sacramento–San Joaquin River Delta end of the Delta. Currently, freshwater entering the Delta has to flow through a maze of river channels and sloughs before entering the Clifton Court Forebay north of Tracy, where water is pumped into the California Aqueduct and Delta-Mendota Canal. In addition, large numbers of Delta smelt and other endangered species are killed by the pumping plants that provide water for the aqueducts. The current proposal, known as the Bay Delta Conservation Plan, entails building twin tunnels under the delta and is closely associated with Governor Jerry Brown. However, the Peripheral Canal proposal has been criticized because it would further