Murky Boundaries of Federally Regulated Waters

I will do my best to stick to scientific matters rather than political opinions in this blog, but I have some specific beefs with the Trump administration based on the intersection between science and policy. I’m specifically opposed to a number of Trump’s proposed changes in his recently released budget proposal; to his appointees running the Department of the Interior and EPA, who are rolling back both environmental data collection and planning for climate change; and to Trump’s executive order regarding the Clean Water Rule. I will discuss some of the implications of cutting EPA’s funding by 30% and rolling back climate change rules on a different post – note that this directly affects my work as an environmental consultant, so take my opinion with a grain of salt – but I want to focus here on the Clean Water Rule and the controversy around it.

The “Clean Water Rule” was finalized under Obama’s EPA in 2015, and attempts to clarify one of the muddiest parts of the Clean Water Act, which turns 45 this year. The Clean Water Act empowered the government to regulate “navigable waters of the United States”, which is well and good, but most water in the U.S. is not navigable per se. Does this mean that if you don’t bother to dredge channels to keep them open for navigation by boat, that they don’t need to be kept clean? No, the Supreme Court has clarified, most recently in 2006, that “waters of the U.S.” include those water bodies with a “significant nexus” to navigable waters.

Although marginally clearer than the Clean Water Act language, this definition still presents challenges to those who work in the realm of science, rather than the realm of law, on a day-to-day basis. For example, a good water scientist/engineer is well aware of the hydrological connection between surface water and groundwater, wherein surface water can flow into or “recharge” groundwater, as well as the opposite behavior where groundwater flows into surface water. The influence of groundwater means that surface water bodies that appear otherwise unconnected may have a fully operational subsurface pathway between them, which may even govern their flow.

The other scientific wrinkle to the definition of “navigable waters” is that the pollutants in major rivers and lakes in the U.S. often originate from smaller creeks, channels, wetlands, and groundwater, which flow into the major bodies of water. Some of these, particularly in the American West, are ephemeral, so they’re only potentially navigable some parts of the year. So, if you’re limited to regulating navigable waters alone, you may not be able to control the inputs of pollutants to the water bodies.

The EPA under Obama attempted to clarify this rule, to set boundaries on what is and is not a body of water with “significant nexus” to navigable waters. Here’s where things get controversial. Let’s say you have a channel in your backyard that drains your septic system or your small organic chicken coop (I practically live in Berkeley). If that channel flows into an ephemeral creek, which flows into, say, San Francisco Bay, which is navigable, you could potentially be in violation of the Clean Water Act for discharging pollutants (in this case, nutrients with no place to go, which will lead to algal growth in the creek or the Bay). But, how could this happen to me?!! You, the septic system/chicken coop discharger, may seem like small potatoes, but these pollution issues are classic examples of the “tragedy of the commons”, and in fact, lots of smaller/moderate dischargers have a disproportionate effect on downstream water bodies, even those that are major drinking water supplies, as shown in the maps on this website. Hate to break it to you, but yes, your hypothetical septic/chicken coop discharges matter, when you measure the mass of pollutants you discharge to the larger body of water.

Lots of industries, including oil companies, developers, ranchers, and farmers, consider the Clean Water Rule to be a government overreach, because it would require new permits for filling in or modifying surface water bodies that had no reason to be federally regulated, in their opinion. The Trump executive order, issued February 28 of this year, requires Secretary Pruitt to review the Clean Water Rule, with the purpose of rescinding or revising it to refer to a different Supreme Court definition of waters of the U.S., this one a very narrow opinion offered by Justice Scalia. According to this amusing article, Scalia’s opinion came from looking up “waters” in the dictionary:

In his plurality opinion, Scalia pulled out the Webster’s New International Dictionary 2nd Edition and looked up the definition of “waters.” It “includes only those relatively permanent, standing, or continuously flowing bodies of water,” he wrote, like “streams,” “oceans, rivers, [and] lakes,” not water that “flows intermittently or ephemerally.”

The rub is that Obama’s Clean Water Rule has already gone through the rule-making process, including public comment/review, and has been made into law. It has, of course, also been held up by court challenges since 2015, but it would be naïve of the Trump administration to assume that their preferred definition of “waters of the U.S.” would pass muster without similar immediate legal challenges. And, as the article above notes, Justice Scalia is no longer on the Supreme Court, whereas Justice Kennedy, whose “significant nexus” language forms the basis of current interpretation of the Clean Water Act’s jurisdiction, is alive and likely to weigh in on any challenges that make it to the Supreme Court.

So, Mr. Pruitt – feel free to begin the arduous challenge of rescinding/rewriting the “Clean Water Rule”, but good luck finishing it quickly in a manner that will hold up in court.

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.

a long way to go

Hello again, readers!  I’m finally rejoining the world of blogging, now that it’s been nearly 6 months since my last post.  In the meantime, I got married and changed my name — I’m now Claire Farnsworth Wildman, but otherwise blog content should remain unchanged.  I’m going to try to get into posting again once a week, and throw some links on my twitter feed when I can’t get to posting on interesting news.  Hopefully this will work!

~ Claire

So today’s post is a comment on China’s limited water supplies.  Bloomberg is noting that China’s coal mines are beginning to feel the crunch of limited water.  China has a fundamental problem that a bunch of development (agriculture and cities, and apparently many coal mines) is in the north, whereas the majority of their rainfall and streamflow is in the south.  This is not too different from the issues of the American southwest, where cities in dry areas keep expanding on the premise that they can access water from distant snowfall in the Rockies or Sierras via rivers and aqueducts.

The difference is that the US generally has pretty decent water resources (9,044 cubic meters = 2.4 million gallons per capita), but China’s are relatively sparse (2,093 cubic meters = 0.55 million gallons per capita), so moving water around won’t ultimately resolve all of their issues.

What struck me in the above article, though, was this: “…Veolia Water, which treated 1.2 billion tons of waste water in China last year…”  That sounds like use of numbers to imply large volumes of treated wastewater…but remember, China has 1.354 billion people as of January 2013.  So, one of the world’s largest water and wastewater treatment plant operators treated nearly 1 ton of wastewater per capita in China last year.  Let’s put that in perspective: an American city with low water use has about 150 gallons per day per capita, which we can assume goes to the wastewater treatment system.  This number is probably way too high for per capita water use for places without reliable drinking water supplies, but let’s use it for a back-of-the-envelope calculation:

150 gallons/day/person x 365 days/year x 8.34 lbs/gallon / (2000 lbs/ton) = 228 tons of wastewater per person in the US

Ok, again, very rough numbers.  Per capita water use is tricky to measure, but this website cites a 2006 UN Development Program report to suggest China averages something like 23 gallons/day/person (quoted as 86 liters/day/person).  Plug that in to the above equation, and you come up with 34 tons of wastewater per person in China, not including industrial wastewater.  Again, one of the world’s largest wastewater treatment companies was proud to hit the target of ~1 ton per person last year.  Whatever the per capita water use in China, it sounds like wastewater treatment has a long way to go…

bad timing for grand ideas

I’ll take a brief respite from my recent oil pipeline kick (more to come later this week) to compare two different news stories: one is the continuing saga of water management struggles in the Missouri-Mississippi River basins, and the other is the attempt to track down new water management strategies for the water-poor, population heavy Front Range region of Colorado.

Over in the Missouri and Mississippi River basins, stakeholders continue to fret about the balance of water flowing through their reaches.  Farmers in North Dakota worry about sufficient irrigation water in the future, as the Army Corps of Engineers considers depleting the 12 years of supply stored in the Upper Missouri’s reservoirs.  (Note to Hetch Hetchy restoration advocates: that’s a lot of supply to be stored.  Engineers must think that excess storage is a hedge against uncertain future conditions, huh…).  Barges in the Mississippi are cutting down their loads, so they can ride higher in the river, and dredging activities to remove natural limestone features along the Illinois-Missouri border have been accelerated.  Don’t let the title of that article fool you — the only water wars in progress are figurative, not literal.

Things could escalate — though almost certainly not to actual violence — if a proposed plan to build a pipeline from the Missouri River watershed to Colorado’s Front Range goes through.  The US Bureau of Reclamation (USBR) is entertaining far-fetched ideas to address Colorado’s limited water supply, including towing an iceberg to California, shipping giant bags of water from Alaska, and yes, building a giant pipeline across Kansas to Denver.  In order to consider these odd ideas seriously, the USBR has started the planning and alternative evaluation process.  I outlined how this generally works in relation to the Hetch Hetchy restoration idea, but suffice it to say, this pipeline is still at the early stages of “tools for decision making” rather than the early stages of design and implementation.

Although this idea isn’t as far-fetched as it first might seem (the pipeline would need to be roughly 600 miles long, only 50% longer than the 419-mile long Los Angeles Aqueduct), I really hope it doesn’t make the next cut for analysis.  The goal in the US should not be to emulate California’s extensive aqueduct network, but rather to implement large-scale water recycling to cut down on net consumption of water by various municipalities or regions.

The timing of this idea is also about as bad as it gets.  Any sign of the Missouri and Mississippi stakeholders getting wind of this idea, and an all-out media war of words will likely ensue.  That’s a good way to ensure that regardless of the engineering feasibility study outcome, the public relations battle will already be far lost.  And who knows, maybe that’s what USBR really wants, too.

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.

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.

follow the yellow brick road

To follow on Wednesday’s post about management of San Francisco’s water supplies with and without the Hetch Hetchy Reservoir, I would like to put my consultant hat on.  (Ok, admittedly I am a consultant, though a new one, so the hat isn’t a stretch.)  Let’s talk about project management.  Major engineering projects require studies and paperwork before actual construction can begin.  In the case of potential O’Shaughnessy Dam removal, I have consulted the California Department of Water Resources (DWR) for planning stages.  The DWR studied the dam removal in 2006, compiling all the previous research to date, identifying gaps in the research, and recommending a path forward for further studies.  This is how they say things are done:

DWR’s description of what each level of study means and entails.

  1. Complete concept level studies.
  2. Complete appraisal-level studies.
  3. Complete feasibility-level studies.
  4. Complete detailed studies and programmatic documents.
  5. Complete environmental impact report and site-specific design engineering.

[See the image to the right for the difference between these levels of studies.]  So far, the concept level studies are partly complete for water replacement, power replacement, physical dam removal, valley restoration, and the future public use plan.

Thus, using our study definitions, most of the prior work is, at best, at the “concept level” of study. That is, the body of work to date, including the state’s work on the potential costs for the potential project, is not sufficient to support sound public policy…Completing all aspects of existing studies to a common level (concept or appraisal) would be a key milestone in the decision-making process, by providing a basis for recommendation to either terminate the study or proceed with feasibility investigations.

Translation: do some more studying to get everything up to par, then continue with in-depth studies about the feasibility of dam removal.  Then, if everything still looks good and the costs are acceptable, start your EIR and design engineering.  (Note that the EIR could still get rejected at the end of everything, just as a warning.)

Ok, so this is the path forward.  My understanding of the ballot measure, based on newspaper reports rather than the vague language of the ballot measure itself, is that San Francisco would spend no more than $8 million on the concept-level studies, then have a vote in 2016 about whether to go forward with dam removal.  That’s unfortunately not how things are done.

As listed above, the concept-level studies lead to feasibility studies, after which the go/no go decision can be reasonably made.  With concept-level or appraisal-level studies in hand, you can continue studying or rule out the project — you can’t start to design or build.  The DWR estimates that the concept-level study would cost $7 million in 2005 dollars.  The appraisal-level study would be another $13 million, the feasibility studies another $32 million, and the detailed studies/programmatic documents another $13 million.  To be clear, the DWR estimates another $58 million in expenses just to get to EIR and design phase.  I would estimate this to work out to nearly 10 years of work.

The total cost of dam removal is estimated to be $3 -$10 billion (2005 dollars) in the 2006 report.  It’s pretty reasonable to expect to spend roughly 1% of that price ($60 million) to determine whether the project should proceed, rather than just 0.1% ($8 million).  (For perspective, they estimate $3-6 billion to restore the Salton Sea, $1-2 billion to deal with Owens Valley, and $10-16 billion to meet California’s flood management needs.)

Look, the guys who drafted Proposition F have the right idea — they want San Francisco to recycle more water and manage stormwater better.  I approve of that.  But they’re pushing on this the wrong way.  I spoke with an employee of Kennedy/Jenks, the firm that designed San Francisco’s state-of-the-art water recycling plant earlier this year.  The firm has twice gotten to the design stage of the plant (that’s step 5 above), only to be killed at the last minute due to concerns about the plant’s location in the city.  It takes a lot of money and time to get to construction design stage, and then have to restart at a new location.  Spend that $8 million on an education campaign so that the next design iteration doesn’t get killed by NIMBY.  And building the extra infrastructure first means that the Bay Area won’t undergo water shortages every ~5 years while the projects are sorted out.

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.