The main stem of the Eel River snakes northwesterly some 200 miles through canyons, forests and verdant farmland, gathering water from its many tributaries as it travels from its headwaters in the Mendocino National Forest to its terminus at the Pacific Ocean south of Humboldt Bay.
But this year, just 10 miles short of its final destination, the river vanishes from view as it passes by the small city of Fortuna, a sign that three years of drought is affecting traditionally water-rich Humboldt County, where the average annual rainfall of 55 inches is more than twice the state’s average.
Other factors, including sediment deposits in the river and escalating water diversions by marijuana cultivators have contributed to the rare, disappearing Eel River incident, according to state and federal fisheries authorities.
The river disappears but it does not actually cease running. It continues flowing under a deep gravel bed before reappearing 300 to 400 yards downstream, said Matt Goldsworthy, a fisheries biologist with the National Marine Fisheries Service.
“Some people are saying it stopped flowing,” he said. But “the water is still flowing below the gravel,” he said.
The differentiation means nothing to migratory fish, which, unless it rains soon, won’t be able to get past the barrier and head upriver to their spawning grounds this fall. That problem could turn out to be a blessing in disguise given the river conditions, Goldsworthy said, noting that the upstream spawning grounds may not be viable because of the drought.
The fall salmon run had not yet begun, so the barrier is preventing fish that are currently in the ocean from getting trapped in shallow, warm pools upstream, where they’d likely die, he said. Similarly, most of the out-migrating juvenile fish have already made it to the ocean.
“The timing is pretty good for fish,” Goldsworthy said.
If rain continues to shun the North Coast, there will be negative impacts to the fisheries, just not as dire as it would be had the timing been less fortuitous, he said.
It’s not uncommon for rivers and streams to disappear under ground for short stretches, but it’s a rare occurrence for the main branch of the Eel River and so close to the ocean, Goldsworthy said.
“Little reaches go dry. Usually it’s further upstream,” Goldsworthy said.
It last occurred at Fortuna, a city of 11,000, in the late 1980s, said state Fish and Wildlife spokesman Clark Blanchard. The bar at the mouth of the river also closed up that time, he said.
So far, cities and most farmers in the Eel River valley appear largely unaffected by the river’s decline. Despite near historic low flows in the Eel, only minimal, state-mandated water restrictions are in effect in towns, and agricultural fields are lush from irrigation operations that farmers in Mendocino, Sonoma and the Central valleys — where drought has made water a precious commodity — can only dream about this year.
Water users in Rio Dell, a small town upstream of the dry stretch of river, were briefly ordered to reduce water consumption to 50 gallons a day because of low river flows, but the state lifted the restriction after the city demonstrated there were no registered senior water rights holders being affected by its use.