wake up call on the Colorado River

I try to keep up with the latest news, but by no means could I use this blog to break news.  That said, developments in the past couple of days are must-reads for anyone interested in water resources.  The water in the southwest is just not there this year, folks, and it’s starting to dawn on people how precarious our water supplies can be.  The simple case is San Luis Reservoir, which supplies much of the South Bay – wealthy homes in Los Altos, Saratoga, and Cupertino, as well as industries in Silicon Valley.  The reservoir is at historic lows — 17% of full pool — because of one of the driest rainy seasons on record, combined with cutbacks in flows out of the Sacramento-San Joaquin Delta have cut off much of the typical inflows, while outflows, in the form of residential, industrial, and agricultural demand, continue unabated.  This year isn’t the year that water will have to be rationed within the San Jose area, according to officials, due to extra storage on-hand in groundwater and smaller reservoirs, but the Santa Clara Valley Water District should be pushing for conservation among its customers and a resolution to the long-term plans for the Bay-Delta, such as the tunnels, perhaps, to shore up their water reliability…

The reliability of the Colorado River’s flow has been debated since the first compact over-allocated the water rights based on wetter than average years.  We’re in a 14-year drought on the Colorado, and now 40 million people’s drinking water and some 15% of the nation’s produce depend on it.  Remarkable numbers, but that’s what happens when there’s only one “major” water source in a 7-state region, and it’s not even one of the top 25 rivers in the US in terms of discharge (at 1400 cubic ft per second on average, the Colorado is #28 of America’s 38 rivers over 500 miles long).  Lakes Powell and Mead, the largest two reservoirs in the US, help bridge the gap between high and low flows on the Colorado, but both are struggling to keep pace with the drawdown of the past 14 years.  Again, inflows are limited, and outflows just keep coming.

The Bureau of Reclamation, which operates both reservoirs, announced on Friday that less than 10% of the normal allocation would be available from Lake Powell this water year (starting October 1st), the lowest amount since the reservoirs were first filling in the 1960s.  This sets the stage for a legal “shortage” (also known as a “call”) to be declared in the next couple of years, which kicks in provisions to cut off water to Arizona, California, Nevada, and Mexico.  Arizona, last in line for water rights, loses supplies first, followed by Nevada and California.  Arizona will rely on its banked groundwater, stored in the “good years” of high runoff.  Las Vegas, which pulls supply from Lake Mead and discharges its treated wastewater into a tributary of the lake, will kick into gear a controversial plan to build a $7 billion pipeline to a groundwater resource in rural eastern Nevada, along the border with Utah.  And California’s farmers in the Imperial Valley, the largest consumers of Colorado River water, will have to be careful about taking only as much water as they’ve been allocated.

This can’t be a surprise to those who’ve been paying attention, from the Bureau of Reclamation’s farfetched feasibility study released last winter to the paper out of Scripps in 2008 that predicted a 50% chance that Lake Mead would be dry by 2021.  Savvy water managers across the southwest have been preparing policies and working out deals for what to do when the inevitable water shortage hits.  Thankfully this means resolution in a meeting room rather than in a court room.  But let’s hope that the public’s eye doesn’t forget this wake-up call if we have a particularly wet winter and seemingly resolve our troubles with plenty of water to go around.  We had a very wet year in 2011, which increased Lake Mead around 40-50 ft, and Lake Powell around 50 ft.  The problems did not go away; the “shortage” risk was merely delayed.

Las Vegas takes charge

The Colorado River is over-allocated, such that in any given year, states only receive a fraction of the quantity of water they were originally promised in 1922 (they also promised nothing to Mexico, but have subsequently revised that part).  I’ve been pretty skeptical that any major treaty would be able to modify that treaty, since so many people are fighting over the water.  But a new pact is set to avoid any international standoffs in the Colorado River basin, between the US and Mexico, and my favorite water manager, Pat Mulroy of SNWA is behind things again.

Las Vegas is in a tight spot, in that it gets its water supply from pipes in Lake Mead, and the lake levels have been declining to levels that threaten to go below the intake pipes (their straws would be sucking air, rather than water, at that point).  Uh-oh for Las Vegas.  So the city is motivated for all downstream Colorado River compact states (Nevada, Arizona, and California), and now Mexico, too, to store as much water as possible in Lake Mead.  (Note to Cadiz, Inc: You’re fighting an uphill battle — Nevada will practically pay California to store water behind Lake Mead…)

Under the agreement, negotiated by UN-style earpieces for translated dialogue, Lake Mead will store Mexico’s excess water in wet years, and allow withdrawals of that “bank” in dry years.  Mexico will also be able to store much of its water supply there temporarily for the next 5 years, while improvements are made to irrigation canals that were damaged in a 2010 earthquake.  Las Vegas and other municipalities will also pay for improvements to Mexican canals to decrease losses, and then use the quantity of water that was formerly “lost” from the system.

Some people don’t just wait for disaster to make opportunities — they plan for worst-case scenarios.  Las Vegas has a plan on the books to build another pipeline into Lake Mead, once the lake hits a certain low level.  By signing practical, clever deals like this one — which, by the way, are a win-win all around — they forestall that expensive construction item, and enhance the reliability of the system for everyone.  Mexico has also avoided the cost of building its own reservoir south of the border, which is significant.

Apparently water managers from Australia, Asia, and Africa are already interested in borrowing language and ideas from this pact.  Props to SNWA for taking the lead and seeing this important deal through.

please put this lady in charge of everything

Las Vegas is known as a water-intensive place in the middle of the desert — the fountains in the Bellagio, the canals at the Venetian, the pirate ship at Treasure Island.  But you might be surprised to know that its per-capita water use is tiny.  The city uses 3% of the state’s water and produces some 70% of its revenue.  How does that happen?  Well, there was a multi-year drought about 20 years ago that brought this to the forefront of developers’ minds (they were required to attach proof of water supply to their development plans and SEC filings).  Also, the regional water agencies merged to form the Southern Nevada Water Authority, and they put this woman in charge: Pat Mulroy.

Pat Mulroy, in my opinion, is one of the savviest water politicians in this country.  Because of its location, Las Vegas has had to adopt cutting edge water recycling technology (water comes out of a pipe in Lake Mead, gets used in Vegas, and discharged to Las Vegas Wash, which runs back into Lake Mead) as well as cutting edge policies to convince locals to dig up grass lawns in favor of desert landscaping.  SNWA has a very high-level analytical lab to make sure that trace organic compounds aren’t reaching the drinking water supply.  And Mrs. Mulroy has worked with regional water agencies as well as the other 6 states in the Colorado River Compact to come to an agreement about what to do when a major drought hits the southwest.

I had the pleasure of meeting Pat Mulroy, back at Eawag in Switzerland, where she kept an international audience rapt with her stories of getting things done and water policy-making in the “wild west”.  But you can see her give a talk at the recent WaterSmart Innovations Conference or just read the transcript of an interview she gave.  Either will give you a sense for her shrewd, yet no-nonsense manner.  I’m hoping that some bigger-name politician will recognize her for her work and make her Secretary of the Interior, so the country could have a truly sensible and effective federal water policy.  Heck, I’d elect her President based on what she’s been able to accomplish…

Who deserves the water?

Something that I’ve been thinking a lot about recently is water.  Typical.  Specifically, where major American cities get their water.  European cities were historically built on rivers or lakes, where an obvious clean water source could be found.  They developed common sense procedures like withdrawing drinking water upstream of discharging wastewater.  In the US, major cities also developed on rivers, but city planners looked further afield to remote unpopulated water basins to deliver higher quality and sometimes greater quantities of water.  In fact, even today, the highest rated tap water, according to its consumers, comes from New York City, which tapped watersheds up to 163 miles away in the Catskills, and San Francisco, which tapped the Hetch Hetchy reservoir in what would later become Yosemite, 167 miles away.  The east side of the San Francisco Bay, which includes Berkeley, where I currently live, and Oakland, where I currently work, gets its water from one watershed north of the Hetch-Hetchy basin.

In light of this reality, maybe the diversion of the Owens and Colorado Rivers into the Los Angeles Aqueduct and Colorado River Aqueduct, respectively, isn’t so bad – it’s just a longer distance (419 miles and 242 miles) than the aqueducts used by the “environmentally conscious” San Francisco Bay Area.  And Atlanta, my hometown, can’t really be blamed for taking as much water as possible from the Chattahoochee River just to the north.  The city is located in a relatively resource-poor area when it comes to surface water, and the Supreme Court recently affirmed its right to the waters of Lake Lanier (though the exact quantity is still TBA).

Las Vegas is located essentially on Lake Mead, and gets its drinking water from the lake as well as discharges its treated wastewater to the lake.  Is this more sustainable than Phoenix, whose recent growth relies on the availability of the Colorado River, 336 miles away?  I’m having a hard time judging cities in their pursuit of water resources from remote, pristine areas, because very few American cities are located adjacent to sufficient water supplies.  Environmentalists in San Francisco bemoan the fate of the salmon in the Sacramento-San Joaquin delta, whose habitat is shrinking due to water grabs from southern California and the Central Valley, but their water comes from an area that was literally made into a National Park!  Water supply inevitably involves some big tradeoffs, so “Let he who is without blame cast the first stone”…

future water supplies

Long term water supplies in California are quite limited if we continue to use water at present rates and the population grows.  The engineers and regulators know this, and theoretically so do the farmers and politicians.  We’ve already overallocated the Colorado River, such that it vanishes into the sediments at its mouth, no longer flowing directly into the Gulf of California.  And wet years for the Sacramento-San Joaquin River watershed doesn’t mean as much for the river flowrate as it does for the downstream farmers in the Central Valley who want to irrigate as much of their land as possible, or for the southern California utilities who want to store the extra water for drought conditions.

On top of expected in trends in population growth, climate change could potentially decrease the precipitation and/or streamflow in most of the southwest.  Furthermore, environmental concerns are pushing water regulators to scale back the allotted flows in the California and Colorado River aqueducts.  If you were the water manager for the city of Los Angeles, what would you do?  The net balance of your inflows is likely to decrease, while the delivery people demand is increasing…

There are a couple of options for new water supplies.  One is to build massive desalination plants, at a high energy cost and a high environmental cost for the disposal of brine waste.  In California you also run into the problem that necessary locations on the shoreline have really high property values and a bunch of neighbors screaming NIMBY.  Another is to look for temporary solutions like underused groundwater basins or watersheds.  Las Vegas is in the process of shipping groundwater from a remote valley of ranchers along the Nevada-Utah border to its water supply.  There’s also a project to mine a groundwater basin in the Mojave Desert in California, between Joshua Tree and Death Valley, for water supply to the L.A. basin.

But to me, the most reliable long-term option is indirect water reuse, which is already in place in Orange County, a relatively conservative portion of southern California.  I am slightly skeptical of direct reuse of wastewater effluent, even when treated beyond normal potable water standards, just because of the lack of a buffer or factor of safety if anything goes awry at the wastewater/water treatment plant.  But indirect potable reuse makes a lot of sense: treated wastewater is injected into a storage basin, most often an aquifer, and then after some flow distance, it is re-extracted as raw water for drinking water supply (i.e., it gets treated again after extraction).  During its travel in the subsurface, the water is filtered naturally by the soil and mixes a little bit with the native groundwater.  Quite a few cities employ this system with lakes, notably Las Vegas, Milwaukee, and Berlin (Germany), but there’s a lot more mixing and dilution in lakes than in groundwater.

To be honest, the indirect reuse in Europe, which has been working in some cases for over 120 years (see Berlin), is very convincing to me.  Water recycling could regenerate roughly 50% of the water supply of the entire L.A. basin (a lot of water is lost to outdoor uses like pools and lawns), and would make water supply as reliable as the wastewater supply.  An odd concept, perhaps, but in the case of Los Angeles this would be less wasteful than all the treated wastewater currently discharged to the ocean.  Given the right geology, water recycling would also require far less infrastructure than desalination plants or large water pipelines.

Would the public go along with this, if properly informed?  Sydney, Australia provides an example of the PR gone wrong – after a contentious public debate, they built a massive desalination plant.  But again, Orange County is already employing this successfully, so we should be able to point to them as a model.  As Orange County goes, so goes the country?  It’s not something I would normally expect to hold.