Seeding was not found to be effective in increasing cover or reducing sediment yields on burned areas in the Colorado Front Range compared to controls, even for storms with return periods of less than one year.
12.
For example; approximately 300, 000m3 of gravel is extracted from the San Luis Rey River in South California every year, which is almost 50 times more than the bedload sediment yield after the dam was built.
13.
The creation of reservoirs has significantly reduced the sediment yield of many rivers as sediment that was entrained in the flow is stopped by a manmade barrier and the energy required to transport the material is lost, the sediment is no longer entrained as there is no flow or the flow is too slow.
