12/8/2020 - Lead Park Ranger at Lake Mendocino, Poppy Lozzoff, admitted that the water level at the lake looks terrifyingly low. “As a visitor, it is a dramatic site to see so much exposed ground,” she wrote in an email.
Lake Mendocino currently sits at 712 ft above sea level. That’s very low. But despite years of dry conditions and the fact that California water year 2019 to 2020 was the third driest in the Upper Russian River watershed in recorded history, it’s not the lowest the lake has ever been. Which is thanks to FIRO, or Forecast Informed Reservoir Operations (pronounced FEE-roh) — a satellite weather forecasting tool to manage water availability and increase water reliability. Without FIRO, there may have been a water shortage this year.
Lake Mendocino is the location of the first ever FIRO trial. For over six years, government agencies and academic institutions have been testing FIRO out at Lake Mendocino. They’re trying to find out, in light of years of droughts and floods, if the new management tool will be feasible to use across the west to more efficiently manage water.
Lake Mendocino is a man-made reservoir that was created when the Coyote Valley dam was constructed in 1958. Because the lake is artificial, water managers can control how much water is released or stored and when.
Before the arrival of FIRO, the lake was being managed based on a manual from the 1950s that had last been updated in the 1980s. FIRO’s forecasting tools allow water manager to better dial in how much water to keep in the lake at any given time.
Without FIRO, the lake would have sunk to its lowest elevation of all time and have 18% less water than it does now, according to Lozzoff and other officials familiar with the project. Army Corps Engineer Nick Malasavage, who has been with the project since its inception, said that if not for the use of FIRO, there likely would have been a water shortage and therefore limits placed on businesses and people that rely on Lake Mendocino water.
However, even with FIRO and the technology it brings to the table, the Russian River water system, which includes the lake, is still being stretched thin by climate change and subsequent drought. This year, the Army Corps of Engineers, which manages the lake, had to reduce flows going into the Russian in order to keep sufficient water storage in the reservoir.
During water year 2019 to 2020, which came to a close on September 30, the region around the lake received 34.8% of normal precipitation, compared to historical averages from the last 127 years. That number comes from measurements at the Ukiah rain gage. As climate change continues to bring more extreme weather conditions — fewer, more intense storms during the rainy season and hotter, longer dry spells during the summer months, data and forecast based water management will become increasingly important. However, it’s not a silver bullet to providing reliable water in the west. FIRO is complicated, and each reservoir is impacted by a variety of factors including climate and users. Applying FIRO principles to other bodies of water around the west and the country will not be an easy feat.