Walla Walla hills Credit: Credit: Wikipedia
With fracking and droughts on the rise, it's easy to find headlines bemoaning the poisoning and depletion of aquifers. This, however, is a story of redemption. Such stories, of course, must start with the problem.
The Northwest — mercifully — lacks a significant fossil fuel extraction industry, so we are spared any problems from fracking, but we certainly have our share of thirsty crops and people, and these definitely cause depletion problems in the arid lands where most of our crops are grown.
The most recent poster child for this is the Odessa area. With the groundwater Odessa farmers relied upon virtually inaccessible, the solution there has been the typical one: Create a large project and give them a chunk of the Columbia River during their growing season.
In the Walla Walla River basin, though, things are different. It's been almost a decade since the area has seen that kind of water depletion. That's not because of any kind of natural abundance, but because the region has come together around a unique plan to recharge its aquifers: by capturing excess flows in the river, and letting the water soak into the ground.
For over a century, the Walla Walla River ran dry in the summer, and many springs and the streams they feed began running dry, too. Volunteers were forced to relocate fish stranded in disconnected pools.
The trouble for David Lee and his dad, both farmers, began in the late 1980s. The Lees had farmed a plot north of Milton-Freewater, Oregon, on the Washington side of the state line. They rotated corn, alfalfa, grass seed and onions, among other crops, without any unusual problems for 20 years. “We had more water than motor to pump it,” recalls David. Then their well started to produce less water in the mid 1980s.
The Lees were not alone. As agriculture grew and consumed ever more water, local irrigation districts began lining ditches and piping water so that less was lost to leakage. These measures actually accelerated the decline of the aquifers, since leakage contributed to their recharge. Those dependent on wells suffered a more precipitous decline in performance.
Meanwhile, without enough water in the river, bull trout and steelhead populations also declined.
Then something unusual happened. In 1994, local stakeholders, having witnessed the antagonism stirred up during a similar situation in the Klamath Basin, formed an uneasy alliance called the Walla Walla Basin Watershed Council to negotiate a more peaceable approach. The members, comprised of environmentalists, irrigators, government agencies and the Confederated Tribes of the Umatilla Reservation (CTUIR), were still in the discussion stage when things came to a head in the late 1990s.
Bull trout and steelhead were listed as threatened species, and several environmental groups, noting the inadequate flows for fish, threatened irrigators with a lawsuit.
Rather than fighting the problem out in court, irrigators agreed to leave enough water in the river for bullies and steelies to dodge extinction. This staved off the suit, but was insufficient to truly restore fisheries there. The Confederated Tribes longed to see the Chinook return, and for that, the agreed-upon rate would need to be doubled.
This being a compromise, no one was entirely happy. And now even farmers with surface water rights were facing possible shortages. Irrigators redoubled conservation efforts, but area stakeholders concluded they needed a new source of water.
An untapped source flowed right by them during winter and early spring, when rain and melting snow fuel high flows in the river. Farmers don't use it then, and it's more than fish need. The water hurtles toward the ocean, bypassing the basin's stream branches, sometimes called distributary channels.
“In the last 50 to a hundred years, those channels have been straightened and modified for the benefit of irrigation,” explains Steve Patten, Walla Walla Basin Watershed Council's senior environmental scientist. And people have built levees to protect the towns, as well as putting in headgates on all their diversion structures. "So we now have a system where in the winter, the river is constrained to a main channel," Patten says. "And all that water flows out of the valley extremely quickly, whereas historically, it would have slowed down, spread out through this distributary system, soaked into the ground and recharged the shallow aquifer."
The typical method of capturing the water would involve reservoirs. But reservoir building is a long, expensive and contentious process, with plenty of impacts: Reservoirs occupy land that could be put to other use; water is lost to evaporation and leakage; and fish passage and habitat is affected. There's even evidence that the reservoirs likely emit greenhouse gases as methane escapes in bubbles when the water levels go up and down.
Storing excess stream water underground instead finesses many of these problems, while offering additional benefits. There are three flavors of groundwater storage: shallow aquifer recharge (SAR), deep aquifer recharge, and aquifer storage and recovery. In both shallow and deep aquifer recharge, natural recharging processes are mimicked, but the latter takes much longer — often decades. Aquifer storage and recovery uses an underground formation as temporary storage for water to be pumped back out later.
In 1965, the U.S. Geological Survey's Robert Newcomb recognized that the basin's abundance of porous soil and channels lent itself to shallow aquifer recharge, one of three types of groundwater storage. Ten years ago, the Walla Walla Basin Watershed Council began to run with his idea, testing out three promising sites. Typical SAR sites are simply ponds built over permeable soil. Captured flows are piped through existing irrigation infrastructure to each site. Since SAR runs in the winter, and the water penetrates the ground quickly, evaporative losses are minimal.
“People have been doing aquifer recharge for hundreds of years," says Patten. "Whenever I talk to old-time farmers about our projects, they say 'Yeah, that makes sense. That's what my grampa did, because he knew his wells would perform better if he put water over his pasture all winter long.' ”
Scientific progress has considerably refined our understanding of what's under our feet and where groundwater goes. Newer computer models allow projects to be sited much more effectively.
“We're not so much testing the idea of aquifer recharge, but learning how it is practiced in our valley, because each location is unique based on the hydrogeology,” says Patten. Since the effort involves two states and a tribe, there's an alphabet soup of state and local agencies, which makes the regulatory and permitting aspect of it complex. Permits for the sites must be renewed at intervals of a few years and are dependent on increased flows and no degradation of water quality.
The benefits for most fish and farmers — more water when it's most needed, cooler water and improved water quality — will be realized slowly. Some dead streams that reawaken do so fitfully, sometimes even trapping fish.
There are already some signs that fish, including Chinook, have returned. “We haven't actively been doing fish monitoring, but in some areas I have anecdotal evidence from landowners saying that they've seen some kind of trout in their streams that they haven't seen in years,” Patten says.
Conditions are improving for well owners, too. Lee remembers over a decade of steadily declining performance at his well. “I started sucking air when I watered. I was looking at having to dig my well deeper, and put in a bigger pump, and more clogging, just to pull it out of the ground.” But shortly after the first SAR site went operational seven miles south, in 2004, things changed in the spring: “One day, my pipe was sucking air, and the next day it wasn't.”
Other farmers have benefited, too, if less dramatically, and there are more sites coming online all the time. Three more started up last year, and eight more are proposed.
The latest climate models for both the Northwest and Walla Walla Basin point to less snow and more rain in decades to come. This means even more water will pass by in the winter.
In Walla Walla, Patten and his colleagues think the program is up to the challenge if it remains on track. “We would see either modest increases in ground water levels or at least we wouldn't hurt them any more than they are,” he says.
The Northwest has also seen successful experiments with another approach to recharging aquifers known as aquifer storage and recovery. Those projects can have long-term benefits, particularly for assuring adequate drinking-water supplies. The Seattle area's Highline Well Field started in the 1980s to provide drinking water. Federal Way's Lakehaven Water District is also developing a project for drinking water, and White Salmon in the southern part of the state has a project.
Yakima has been quietly laying the foundation of a particularly ambitious aquifer storage and recovery program, under the leadership of Dan Brown, its Water and Irrigation Division manager. Brown, who has been with department for over 20 years, has also seen the climate forecasts for the Northwest and for his basin. He can see the day when the city won't have enough surface water to go around in the summer, and is preparing for it. A portion of the city's water right is prorated, meaning it wouldn't get all of it in summer drought conditions. The aquifer program will play a big role in addressing that problem.
Yakima's program will put treated water into wells, as do other municipal projects. As with many other projects, gravity is a friend. Yakima sits in a basalt bowl, and its treatment plant perches on its northwestern lip, above 80 percent of the service area, extracting water from the Naches River. Yakima will put treated water into wells below the plant's elevation. Its conveyance infrastructure is designed to work in the winter. The city had pumped groundwater decades ago, and the associated records provided further clues to the feasibility of the aquifer storage and recovery, sometimes called ASR.
As with other surface water-to-groundwater projects, assurance of water quality is key. One could be forgiven for thinking that if the water is already treated, it wouldn't be an issue. “My surface water has a minor amount of disinfection byproducts in it," Brown says. "You always get them when you add chlorine to the water. And those are well under the drinking water standards, but I'm putting it into groundwater that doesn't have any, so am I degrading the groundwater? Well, in the Department of Ecology's eyes, yes.”
Dave Nazy, of the state Ecology Department's Office of the Columbia River, explains how this works out. “Our rule is written in a way to guide towards what we call an overriding public interest determination in terms of meeting groundwater quality standards. Essentially, we look at a cost benefit. Where are all the benefits of this potential project versus the potential costs and risks?” In this case, the tiny temporary degradation of the groundwater by disinfection byproducts appears worth the risk when weighed against the enormous cost of eliminating them. In some ways, adding surface water to the aquifer improves the quality. For example, it has less arsenic. Nevertheless, ASR projects must demonstrate that the disinfection byproducts largely disappear. Fortunately, they do.
Most wells in Yakima will be sited near neighborhoods, but the impact on livability will be infinitesimal. For one thing, each site is only a quarter-acre.
“You build your pumphouse so it looks like a house in the neighborhood,” says Brown, who also notes that modern pumps are quiet. “That one we have in Gardner Park, that's a 700 horsepower motor. That's a big unit. You go outside and shut the door, you almost don't know if it's running or not.”
Brown expects to start with an injection well in Yakima's Kissel Park. “Our goal is to have the reservoir permit in place this November and start injecting water into the Kissel well.” Yakima plans to steadily add wells over coming decades. “In 2050 we won't be taking any water out of the river in the summer, water right or no water right. It'll all have to come out in the winter,” promises Brown.
What an elegant, sweet irony that some redemption for our aquifers might come from one of their problems' causes: wells.