back to blogging

After a long hiatus of being distracted by many other things, I am itching to get back to blogging. Look for more posts coming soon.

As you’ve noticed (since my readers are of course the savviest folks around when it comes to water policy and water use 🙂 ), the drought in California in the past three years has really shifted perspectives on the importance of water reuse, desalination, and managed aquifer recharge. On a professional front, as a remediation engineer, I’m seeing more and more places in Southern California with public pressure not only to clean up contaminated groundwater but to reuse it for potable water supply. It is certainly an exciting time to be an engineer interested in building new projects to provide stability to the water supply in light of changing conditions!

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.

more than physics

People talk about water scarcity like it’s a physics problem: why don’t we tow icebergs from Alaska to alleviate the southwest’s water issues?  what about pumping water from the Great Lakes across the Rockies?  Sometimes that sort of grand thinking works, like the diversion of California’s water resources from the upper Sierra Nevada mountains southward to the Central Valley and Southern California.  But that’s only part of the equation.  One reason that California’s State Water Project and Central Valley Project are successful is that the source is virtually pristine snowmelt.  Move clean water from an area of relative abundance to an area of relative scarcity, add in a comment about humans adapting the environment to their needs, and voila, problem solved!

In my last post, I remarked on China’s limited water resources and their lack of wastewater treatment.  Well, not surprisingly, the Chinese government is trying their darndest to move water around to alleviate chronic water scarcity in the north (think Beijing) with relative abundant water from parts south (think the Yangtze River).  They’re apparently getting close on parts of this great diversion – the Danjiangkou Reservoir should be sending water northward next year.  The physics problem has been solved for a mere $81 billion!  Good job.

One small problem: the water to be transported is currently not fit for drinking.

A water pollution plan issued by the State Council, or China’s cabinet requires that the water quality for all five rivers that flow into the Danjiangkou meet a “grade III” standard by 2015.  But four of those rivers are now rated “grade V,” deemed for “agricultural use only” and the fifth river is considered “grade IV,” for “industrial use only,” reports China’s state-run news agency Xinhua.  “The target is very unlikely to be met as many pollution control projects lag behind schedule due to a fund shortage,” said Cheng Jiagang, vice mayor of Shiyan in Hubei province.

Oh.  What kind of fund shortage, when you just spent $81 billion on construction??

I’ve remarked previously on the lack of fame associated with building brand new shiny underground water infrastructure, and this appears to be a similar problem.  According to the above article, the local government needs about $500 million (just a fraction of that $81 billion price tag!) to build a wastewater treatment plant with nearly 700 miles of sewer pipelines.  So far, they’ve shuttered “329 factories in the last few years, but that has cut revenues by $130 million annually”.

Well, I hope they can find the money.  Until then…good luck to those intending to rely upon the diverted water.  Physics ain’t everything, folks.

mandate for water

California had a few interesting outcomes from the elections a couple of weeks ago, when it comes to water.  Most of these were local ballot initiatives, like the “Restore Hetch Hetchy” proposition I’ve talked about before.  But one that’s a little more subtle is that the state legislature will have a Democratic supermajority to accompany Democratic governor Jerry Brown’s agenda for the next 2 years.  Brown is a moderate Democrat, so he won’t necessarily appeal to all Democrats, but he has set five near-term priorities:

  1. Calibrating state rules and regulations so they don’t discourage job creation and economic development
  2. Continuing work on the state’s high-speed rail project
  3. Evaluating the state’s education framework
  4. Delivering a budget to the Legislature in January
  5. Securing water reliability for the state

That last one is pretty interesting, considering that Gov. Brown has already issued the Bay Delta Conservation Plan, to build two massive tunnels to make deliveries to the Central Valley and Southern California more reliable.  Plus, remember that huge ballot initiative to spend $11 billion on improving water resources across the state, the one that was shelved so Gov. Brown’s education proposition would have more likelihood of success?  Well, the Democrats could pass it now, to the chagrin of small-government Republicans across the state (but on that note, if you’re a small-government Republican — let’s be honest — you live in the wrong state).

The state legislative analyst recently projected lower budget deficits and future budget surpluses for the state,  a first in a long time.  You know what legislators, especially big spenders, will want to do with budget surpluses?  Spend them!  Let’s hope that Gov. Brown’s priorities lead to wise spending on projects that the state needs (and you can guess which issues I’m biased towards…).

skip compact fluorescents – recycle wastewater

An interesting article has recently been published in an open-access journal called “Environmental Research Letters.”  I’m torn on open-access journals: people should have access to research results, but the quality of publication suffers without higher quality reviewers.  That said, this article seems pretty informative.  The authors attempted to quantify the energy used in the US in 2010 for treating and delivering water, and they found a whopping 12.6% of energy consumption in the US is due to water.

I found this figure instructive, showing the difference in energy requirements for various types of water sources and treatment levels.  Note the difference between desalted water and normally treated water is large, but the difference between desalted water and the California State Water Project water (which is pumped from the Bay-Delta to southern California) is small.  No wonder southern Californians are getting more excited about seawater desalination and water recycling, assuming that cost scales with the  energy intensity of the water source.

energy consumption for water supply

With some pretty complicated flow diagrams, the authors come to one very striking conclusion:

We estimate that 5.4 quads of this primary energy (611 billion kWh delivered) were used to generate electricity for pumping, treating, heating, cooling and pressurizing water in the  US, which is approximately 25% more energy than is used for lighting in the Residential and Commercial sectors [40]. (Despite this equivalency, much more policy attention has been invested in energy-efficiency for lighting, rather than reducing hot water consumption or investing in energy-efficient water heating methods, even though the latter might have just as much impact.)

In other words, reducing hot water consumption or investing in energy-efficient water heating methods could have a similar impact to switching our personal lightbulbs to compact fluorescents, yet there has been no policy push to educate people on this aspect.

Results like these are fascinating and instructive.  Once we know where the energy is going and how much our water really “costs”, we can make adjustments that make sense without revamping the whole system.  You and I can be more energy efficient by taking shorter showers and turning water off while lathering up with soap and shampoo.  California can promote water recycling in southern California instead of desalination and increasing imported water, which would save on energy without cutting off the State Water Project.  I’m sure many more examples of efficiency improvements are available — we just have to think a little outside the box.

planning is for squares

I promised an assessment of the Hetch Hetchy reservoir inflows, outflows, and storage, and I intend to deliver something.  I looked into the reservoir, from the data available from USGS to the Restore Hetch Hetchy website to the San Francisco Public Utility Commission’s official position on Proposition F to the California Department of Water Resources (DWR) 2006 study on restoration of the Hetch Hetchy valley.  There are many things out there with opinions, but I intend to highlight the facts.

  1. Storage, inflows, and outflows.  The Hetch Hetchy reservoir has stored an average of 282,100 acre-feet over the past 5 years, with an extreme maximum storage of 363,300 acre-feet and a minimum storage of 154,200 acre-feet.  I can see a couple of jumps in the plots of storage vs. time that suggest the dam is occasionally operated to send water to other locations, so a true picture of the storage in the system would need to include all 8 reservoirs in the system and river flow at multiple locations.  Honestly I don’t have time to get to this.  But I can say that in the past 5 years, the SF utility system has used at least 363,000 – 154,200 = 209,100 acre-feet stored in the Hetch Hetchy reservoir.  The other 7 dams owned by the San Francisco Public Utility Commission (SFPUC) have a combined storage of 537,600 acre-feet [Urban Water Management Plan, 2010].  So just to store the water that was stored in Hetch Hetchy and used in the past 5 years, you would need to use approximately 40% of the remaining reservoir space in the entire 7-dam network, and it’s not like those reservoirs are normally sitting empty.
  2. Water storage needs.  The Restore Hetch Hetchy plan calls for water intake via pipes without the dam.  The storage can be maintained by the rest of the reservoirs on the system.  “Hydrologic analysis shows that it will be possible to fully meet system demands in 4 out of 5 years. In the driest years, 20% of system demands will need to be met from additional water storage or supply resources.”  This is a direct quote from the Restore Hetch Hetchy website.  Let’s examine this.  One in every five years, this new Hetch-Hetchy-free system would experience a water shortage.  Have you ever heard of a utility plan to have water shortages?  We have utilities to provide reliability, and even then 20-year, 50-year, and 100-year events can overwhelm the infrastructure we have.  A 20-year event is a disaster, rather than an inconvenience, when your planning basis is a 5-year event.  Civil engineers like to design for 20-year events, at a bare minimum, with floods like the 1993 Mississippi River flood or the 2005 Hurricane Katrina disaster bringing calls for 500-year and 1000-year designs for water management (in those cases, we’re talking levees rather than dams, but droughts can be equally devastating).
  3. New supplies. The second half of the above quote addresses where additional water supplies will come from in the dry years: “additional water storage or supply resources.”  Let me refresh your memory, San Francisco — California’s water supply is already overallocated.  I just drove down I-5 this weekend and saw farmers’ billboards complaining about “Congress-created dust bowl” with cuts in water supply listed.  Those weren’t Congress-created cuts, those were drought-created cuts combined with a federal judge upholding the primacy of the Endangered Species Act, specifically related to fish in the Bay-Delta, over California’s water allocations.  There isn’t enough water for everything we already want to do.  Please, Restore Hetch Hetchy, tell us where the water will come from.  Water storage measures and water recycling facilities take time, money, and planning, and can’t happen overnight once the dam removal is underway.
  4. Climate change.  Finally, I will just note that climate change is projected to decrease snowpack (nature’s water storage) in the Sierras and increase the frequency and duration of “extreme” events, both rainfall and drought.  To remove excess storage from the water supply system in light of this very real challenge to California’s water supplies is very short-sighted.

That’s enough for now about water flows.  Next time, I’ll tell you what the DWR’s own report recommended for the Hetch Hetchy restoration question.  Hint: it’s not what’s in Proposition F.

where’s the water recycling ballot measure?

San Franciscans will vote in just a few short weeks whether to spend $8 million to study removal of the Hetch Hetchy reservoir in Yosemite National Park.  Since this idea has been studied many times before, and there are no alternate water supplies readily available for the Bay Area (or California in general…), I’ve stated before that this is a bad idea.  I think a far more useful expense of money, energy, and discourse would be when San Francisco is going to get serious about water recycling…

Recently, the town of Novato, in the North Bay (Marin County), opened a 1.7-million gallons-per-day water recycling plant.  That’s not a very big plant, relatively speaking, but it is 1.7 million more gallons that Novato will be recycling than San Francisco, every day.  The article notes that San Rafael, another town in Marin County, also opened a water recycling plant just a few weeks ago.  Neither of these plants will produce drinking water, but rather will supply golf courses and agricultural users.  Fair enough, that means that those guys aren’t using drinking water.

Oxnard, a town in Ventura County, southern California, also recently opened a “world class” water recycling facility capable of treating 6.25 million gallons per day.  Again, so far this facility will meet needs of agricultural and golf courses, rather than drinking water, but this will have the capability to hook into a public water supply, given the high level of treatment that this water will undergo (microfiltration, reverse osmosis, UV, and peroxide treatments…the peroxide seems like overkill to me, but I guess a factor of safety never hurts…).

These places are putting San Francisco to shame.  Virtually nowhere in California can claim to have a water source that did not at some point degrade the environment.  Dams and canals were built.  But the best thing we can do is decrease our reliance on this infrastructure through smart water recycling and aquifer storage.  Only then can we revisit the dams and canals and whether we really need them.  So, San Franciscans, where’s the ballot measure about the city’s lack of any water recycling??

getting your feet wet

Just a quick heads up for anyone out there who is new to the water realm: the Nature Conservancy has produced a cool interactive map with the major water sources and watersheds for California.  You can’t try every city in the state, but you can get a good sense, at least for the big cities not in the Central Valley.  The Nature Conservancy highlights how little of our watersheds are protected from development, to keep our water sources clean, and they’d love you to give them money to keep protecting watersheds, mainly by buying up land in critical areas.  I’m not endorsing them in any manner, but it only seems fair to let you know their angle up front.

This should give a good overview of the major water sources in California.  I hope to begin some posts about Californian water supplies — the background, the shortage, and the proposals out there at the moment — in the next week or two.

the answer is beneath your feet

California is facing some worrisome pressures from increasing water demand for a growing population and decreasing supply reliability due to climate change and environmental pressures on the Bay-Delta region.  What should California do, when faced with extreme drought?  A new study released by the California Energy Commission recommends creating and maintaining a water storage bank underground.  That is, California should store excess water underground, and then pump it out as needed when extreme drought arrives.  I’ve been a fan of this idea (“Managed Aquifer Recharge” or “Managed Underground Storage” are two broad names for the idea) since I first heard about it some 6 years ago in grad school, and it’s great to see that policy advisers and think-tanks are starting to come around.  If we can educate the rest of California, including politicians, then we might actually have a shot at making things happen.

We want solar now!

Apparently some picture of Indians using a photovoltaic (PV) panel above a water canal has gotten some Californians clamoring for PV all over California’s major aqueducts.  Someone ran a rough look at the numbers here.  It is true that harnessing solar energy would offset the energy footprint of moving all that water around, which is not trivial.  But there are a couple of reasons why any water manager should be skeptical of this option, which aren’t widely publicized.

  1. California’s aqueducts, open to the atmosphere, receive a high dose of natural UV irradiation as the water travels, which acts as a natural disinfectant to keep down microbial growth.  This means that the water quality would decrease if the UV rays were captured for energy purposes.  Drinking water utilities would likely need to spend more money (and energy) on water treatment to offset this natural treatment process. (As an aside, this is what concerns me about Christo’s art project in which he wants to drape fabric over six miles of the Arkansas River in Colorado.)
  2. PV panels get dirty, especially in the desert.  You know what they use to clean PV?  Water.  So you’d also lose some of the water to cleaning those hundreds of miles of panels, which at scale is also not trivial.
  3. Finally, there is the cost of PV itself.  Solar projects are notoriously capital intensive, which is one reason that they have a tough time competing with non-renewable energy projects like coal and natural gas, which have higher operations and maintenance costs.  The installation above the aqueduct channels would require new design and likely extra steel to straddle the wide channels, compared to normal solar arrays mounted on single posts.

My guess is, utilities like Metropolitan Water District of Southern California, which owns the Colorado River aqueduct, or the Los Angeles Department of Water and Power, which owns the Los Angeles aqueduct, have done enough cost analysis to determine that the benefits do not outweigh the costs (and the financial risks) in this case.  It’s understandable to me that they would be very conservative when it comes to anything that might disrupt their most valuable resource: water.