These two photographs taken from the same location in the Ballona Creek channel, clearly show the differing amounts of water during both dry weather and in heavy rain.
This photo was taken in July and despite the dry, 90 degree weather, roughly one million gallons flows through the system. This flow comes from overwatering, car washing and other activities. The same location during a rainstorm. Compare the water level along the channel walls to the dry weather photo and it becomes apparent that the flow can increase to billions of gallons of water.