It's obvious to residents in the area that the San Joaquin River is running fast and high, but scientists from the US Geological Survey need to know exactly how much water is going by so they are using some high tech equipment to try and figure it out.
"It's called an acoustic Doppler current profiler that we use to measure the velocity of the water and the depth of the channel, and we combine those together mathematically to give us a discharge," Al Caldwell with the USGS said.
The discharge from the base of Friant Dam was dramatically turned up last week to make room for the storm runoff and keep the dam from overflowing like it did in 1997. Back then, the flow breached the dam and set a record reaching 60,000-acre feet per second.
The current estimate is about 7,000 cubic feet per second. As Caldwell of the USGS explains, a cubic foot is about the size of a basketball.
"Seven thousand basketballs coming past this point at one second, 50,000 gallons of water per second," he explained.
This high water gives scientists a chance to calibrate their equipment. The readings from the new Doppler system will be compared with the standard measuring devices inside the 80-year-old concrete tower in Lost Lake Park.
"So, we are going to verify that and we are going to pin it down to exactly how much water is coming by here," Caldwell said.
Precision is needed because this river provides drinking water, irrigation water for farms, and these measurements will help decide how much can be left over to restore the salmon run that disappeared because of all those other demands decades ago.