KLAMATH FALLS, Ore. — A new Biological Assessment released this week by Bureau of Reclamation aims to help other federal agencies create a 2019 Biological Opinion that guides how to protect ESA-listed species in the Klamath Basin while also providing more certainty for On-Project irrigators on the timetable for water delivery by April 1.
The assessment, hundreds of pages long, has several new aspects aimed at improvements to the Klamath Project operations, such as increased flexibility for water delivery while decreasing the capacity of water that the Project can use in a water season.
“The Biological Assessment — It’s a look at the current state of the environment and the endangered species that might be affected by operation of the Klamath Project,” said Jeff Nettleton, manager of the Klamath Basin Area Office of Bureau of Reclamation. “It was written by scientists from Reclamation, National Marine Fisheries Service, and Fish and Wildlife Service.”
Hoopa, Karuk, Yurok, and the Klamath Tribes also contributed to the process to formulate the document as well as contractors and other key stakeholders, Nettleton said.
The assessment aims to provide irrigators more certainty of an exact water supply date, but that doesn’t mean the water supply will be higher than previous years, according to Nettleton, but would be based on the scientific model for what type of hydrologic water year that occurs in the Basin.
“We would anticipate, at least as it stands in our current proposed action, making the commitment to them on April 1 that this is how much water you have for this water year,” Nettleton said.
Reclamation utilizes the scientific model Nettleton refers to determine how many acre feet the Klamath Project will receive.
But there have been issues with it, according to Nettleton, that he said are addressed in the 2018 model.
“The new model looks at total inflows to Upper Klamath Lake versus the old model, which kind of focused on the inflows from the Williamson River, in addition to forecasting data,” Nettleton said.
“That helps eliminate issues with relying on just the one tributary to Upper Klamath Lake as the signal for the hydrology that we’re getting at any given time.”
Nettleton said Reclamation has also experienced challenges associated with weather forecasts that at first appeared to predict more wet weather than the area actually received.
“That caused problems because the lake obviously was lower at the end of the actual precipitation than they had forecast,” Nettleton said.
Using the actual inflows on a running average for the past 60 days, Reclamation officials will instead calculate inflow data while also utilizing forecast information.
“Our operational decisions going forward will be more reliable because they’ll be less impacted by single storm events or some sort of an abrupt change in the weather patterns that wasn’t forecast accurately,” Nettleton said.
Also included in the model is an agriculture sub-model, which wasn’t included in the previous model, that aims to provide more flexibility for water delivery to the Project.
“That helps us to more accurately model and project the deliveries that will be needed and scale those to the actual Project supply,” Nettleton said.
In the past, Nettleton said water would be shut off to the Project early if necessary due to trouble associated with crossing over legal, end-of-month thresholds. Not so under the new Biological Assessment.
“They still have to stay within the Project supply and they’re still very minimum limitations on the lake at certain time periods, such as the spawning period for the sucker,” Nettleton said. “It would allow the Project more flexibility to determine when they need the water that’s available to them.”
With more flexibility, however, comes a cap on the water delivery amount, according to Nettleton.
“The average Project supply was previously about 390,000 acre-feet and now the Project supply is capped at 350,000 acre-feet,” Nettleton said. “Now that’s out of Upper Klamath Lake.”
The caveat to that supply, Nettleton said, is the additional source of water from the Lost River that the Project can use under the new assessment.
“Under the new Proposed Action, the project supply is capped at 350,000 acre feet, but the project now has access to those flows from the Lost River to utilize,” he said. “That kind of helps make up that difference.”
Nettleton said in the past, 390,000 acre feet has been considered a full delivery of water for project irrigators.
“The average project use in the past has been around 320,000 acre feet if you average all of the years of record together,” Nettleton said.
To put it in perspective, the Klamath Project received about 236,000 acre-feet of water in summer 2018.
The amount of acre feet for a delivery is based on putting the years of hydrology — 36 in total — through a scientific model that generates what the actual project supply, actual flows to the river, and lake levels would be, based on the inflows to Upper Klamath Lake.
“Yes, there would be years where there was significantly less than 350,000 acre-feet,” he said.
Other major objectives included in the development of the ‘2018 Proposed Action and Biological Assessment’ include providing lake and river conditions that are intended to avoid jeopardizing the continued existence of ESA-listed species, Nettleton said.
“That process was accelerated from what our previous timeframe that we anticipated completing this in March of 2020 instead of December of 2018,” Nettleton said.“In the process of abbreviating that, we had to eliminate some of what we’d hoped for as far as additional stakeholder meetings.”