The oldest working door in Britain. We know because tree rings!

The BBC reports on the oldest working door in Britain:

Archaeologists discovered the oak door in Westminster Abbey was put in place in the 1050s, during the reign of the Abbey’s founder, Edward the Confessor.

It makes it the only surviving Anglo Saxon door in Britain.

We most often think about the use of tree rings to study ancient climates (wide rings wet, narrow rings dry). But they’re also commonly used for archaeological and historical research, to date the time when structures were built based on the ages of the lumber used. I wrote a book about this.

Melons, boats, fish: the new Tusher Dam on the Green

Brian Maffly writes this week about the new Tusher Dam on the Green River, a little diversion structure that diverts water to a bit more than 5,000 acres that apparently grows delicious melons. The old dam was in trouble, and the new one has been crafted to expand the range of natural and societal values attached to a 21st century river:

The initial Tusher plan did not call for a boat passage and river runners quickly mobilized, lobbying for features that would enable boaters to replicate the Green River portion of the 1869 expedition led by John Wesley Powell.

Officials agreed a boat passage was warranted and the Utah Division of Forestry, Fire and State Lands (FFSL) put up the $153,000 to help cover increased costs….

The new design also features screens to keep fish out of the diversion canals, as well as three fish passages — one for upstream swimmers and two for downstreamers — equipped with readers to count fish that have been injected with tiny electronic tags. This aspect of the project was funded and designed by state and federal wildlife agencies hoping to recover native humpback chub, Colorado pike minnow, razorback sucker and bonytail.

The inevitable decline of irrigated acreage in California’s central valley

It’s a relatively straightforward point: when there is less water to irrigate farmland, there will be less irrigated farmland. For example, OtPR last year:

As groundwater sustainability agencies have to bring irrigated acreage in line with the sustainable yield of the groundwater basin, they will be retiring irrigated lands (Dr. Burt: 1-1.5 million acres; Dr. Lund: up to 2 million acres). I say 3 million acres, because so far everything we’ve predicted for climate change has been an underestimate.)

But this will be really, really hard to do, because the people irrigating land now would prefer to continue to do so, for perfectly understandable reasons (profit, way of life). And there will be hard tradeoffs in deciding how much less water, and which bits of land. Use groundwater now at the expense of future subsidence and loss of resilience? How much of the environment to protect and enhance with water that could otherwise be used to irrigated crops? Those are questions of values, not science, much as people love to scientize them in the political debates.

But however we do it, and however big the reductions are, they are coming. Jay Lund:

  • The San Joaquin Valley will have less irrigated agricultural land. The Central Valley south of the Delta is a huge productive agricultural region that currently relies on water from the Delta imports, groundwater overdraft, and reduced outflows from the San Joaquin River. Reductions in those sources will decrease water available to this region by 2-5 million acre feet per year, requiring the fallowing of 500,000-2 million acres of this region’s 5 million irrigated acres. Some of this land will be retired due to salinization and urbanization. Continued shifts to higher value crops, especially orchards, will help maintain agricultural revenues and jobs, as they have during the drought.


From the World Bank, hope for our ability to handle climate change’s water problems

A new report by a team from the World Bank offers hope for the ability of most of the world to cope with increasing water scarcity associated with climate change.

Climate change is water change

Climate change is water change

The headlines following the report’s release have been grim: “Global water shortages to deliver ‘severe hit’ to economies, World Bank warns“, to cite one typical example. But for most regions of the world, the study found, there is a crucial caveat – a severe hit to economies if nations do nothing to change their water allocation institutions. In other words, even under the stress of climate change, there is likely to be enough water available for most of the world (northern Africa and the Middle East standing as important exceptions) to still prosper economically if water management institutions can keep up with the changing climate.

Getting the distribution of water right will go a long way toward decoupling water use from economic growth. In many regions, water resources have been over-allocated, and climate change will compound the scarcity. If but a small part of water use were allocated to bring supply and demand into balance, many anticipated problems of climate and socio-economic scarcity could be resolved.

The details of the maps’ geography are important. First, they suggest that even without changes in water governance, the cumulative impact of climate change-caused water shortages will be relatively modest in the Americas. They also suggest that, with good governance, China can prosper under climate change despite its widely reported water problems.

This “getting the distribution of water right” is no small thing. Good governance is hard, and the people living under bad governance face all sorts of problems. Water is just one of them. Climate change creates a world less forgiving of bad governance. But the report suggests that the problem we face is tractable – that there’s enough water for most of the world’s people well into to the future if we can get the water management institutions right.

Early melt in the West’s snowpack

April US temperature anomalies, courtesy PRISM project

April US temperature anomalies, courtesy PRISM project

April and early May have been extraordinarily warm in parts of the western United States, leading to early snowmelt, according to the USDA’s first-week-of-May snowpack update:

During April, Western snowpack dropped at record speed, according to data from the fifth and final 2016 forecast by the U.S. Department of Agriculture’s Natural Resources Conservation Service.

“In the Pacific Northwest, low precipitation and high temperatures led to a dramatic reduction in snowpack,” said NRCS Hydrologist Cara McCarthy. “In this area, peak streamflow is arriving weeks earlier than normal this year.”

Not all areas have low snowpack. “Parts of Wyoming and Colorado have seen much above-average precipitation in recent weeks, causing concerns about potential flooding in the North Platte,” said McCarthy.

This is a critical phenomenon for water management. Mountain snows serve as a terrific water storage reservoir, better than any dam. April temperatures in New Mexico’s northern mountains are averaging 1 to 2 degrees Fahrenheit warmer than they were when we built the state’s water supply infrastructure. (Source: NCDC)

Chamita Snotel

Chamita Snotel

Here in New Mexico, we’ve seen low elevation snowpack thinning rapidly. Chamita, near the New Mexico-Colorado border at 8,400 feet (2,500 meters) elevation, has already melted out, two-three weeks early. We’ve still got some snow at the higher elevations – Wolf Creek up in southern Colorado is a favorite with New Mexico farmers tracking their water supply. It’s at 11,000 feet (3,400 meters) and has held up OK so far.

The relationship between beetle kills and forest fire

In contrast to common assumptions of positive feedbacks, we find that insects generally reduce the severity of subsequent wildfires. Specific effects vary with insect type and timing, but both insects decrease the abundance of live vegetation susceptible to wildfire at multiple time lags. By dampening subsequent burn severity, native insects could buffer rather than exacerbate fire regime changes expected due to land use and climate change.

The area of study is the US Pacific Northwest. The paper is Do insect outbreaks reduce the severity of subsequent forest fires? Meigs et. al, Environmental Research Letters, Volume 11, Number 4


On the use of the word “decoupling”

I’ve been using the word “decoupling” to describe what is happening in the relationship between water use and population/economic growth. The phenomenon is common, and I blog about it a lot – water use going down even as population and agricultural productivity go up.

Now comes Robert Stavins, a prominent environmental economist, to argue that the word is not quite right. He’s talking about carbon emissions, but his argument generalizes to the way I’ve been using the word:

Decoupling is the wrong word to describe what has been happening.  It is simply the wrong metaphor.  When a caboose is decoupled from a train, it stops moving altogether.  A better metaphor, although less linguistically appealing, would be a “slipping clutch.”  The engine continues to transmit power, and as a result the driveshaft continues to rotate, but less than when the clutch was new.


Is the Colorado River community nearing a water-saving deal?

A flurry of public discussion over the last week about a possible water conservation deal on the Lower Colorado River illustrates the central dilemma in the river basin’s water use problems.

tl;dr This is a very important agreement. Modeling suggests that, if implemented, it could slow the steep decline in Lake Mead. The water conservation goals are achievable without crashing the West’s economy, but politics back home, in the individual states, remains the most important stumbling block.

The longer version:

The dilemma is this:

random picture of Hoover Dam and Lake Mead, meant to make it look really empty

random picture of Hoover Dam and Lake Mead, meant to make it look really empty

At the scale of the basin as a whole (seven US states and two in Mexico), the river’s waters are overallocated. Members of the formal and informal governance network of water managers working at that scale all know that everyone needs to take less water.

The question of who takes how much less, and when, is a staggeringly difficult negotiation. But then – and this is the far harder part, the dilemma – the representatives of each state have to go back home and sell that deal to political constituencies who don’t work and think at the basin scale, people who are skeptical of any deal to give up water to which the feel they are entitled.

This is one of the central arguments in my upcoming book (preorder now if your opportunity cost of money is low and you’re willing to wait four months to actually read it) – the difference between basin-facing politics and the domestic-facing politics of water management back home. There is a great deal of evidence that across all water use classes and geographies, communities are capable of using less water without suffering significant harm. But folks don’t always realize this, and at the local level tend to cling to the security of their old paper Colorado River water allocations, even if there isn’t enough wet water to meet them all.

At the individual community level, this is rational. Voluntarily giving up water absent a broad water use reduction deal just means that other users will take more and the system can still crash. Collectively, if everyone acts on this local-level rationale, we’re screwed.

The Deal

As first reported by Tony Davis and then ably followed up by Ian James, Caitlin McGlade, and Henry Brean, The Deal calls for Arizona and Nevada to take larger reductions in their annual Colorado River allocation than are required under the current rules, and brings California into the allocation reduction scheme as well at some point in the future if the bigger Arizona and Nevada cuts aren’t enough to slow the decline in Lake Mead.

Water in the desert - the Colorado River's Parker Strip

Water in the desert – the Colorado River’s Parker Strip

When I was finishing up the final draft of the book’s manuscript last December, the basic shape of the deal was emerging, looking a lot like what we see today. What wasn’t clear (and still isn’t) was whether it could be packaged in such a way that it could be sold to skeptical water users back home in the states. (As a newspaper reporter by training and inclination, this was a tricky problem. We’re used to having the next day’s paper to revise and extend our remarks as things change. How to write something in December, with this uncertainty hanging over the system, that will hold up next September? Buy my book! See how I did!)

It’s still not clear whether this deal can be sold back home, and there remain some subtle unresolved bits: “There are still significant issues that we need to keep working through. So we’re going to keep at it, and it may take several months. It may take another year,” California’s Tanya Trujillo told James.

Selling it in Arizona

It’s emerged into public view now because Arizona’s leadership decided it needs to get on with the task of lining up the political support it will need back home. As I’ve written elsewhere and as I argue in my book (On the shelves Sept. 1! Preorder now!), Arizona’s domestic water politics, especially its hostility toward California, is one of the biggest stumbling blocks to a deal.

Arizona has a long history of hating on California over water, but the biggest sting is the 1968 deal that allowed construction of the Central Arizona Project. The canal was necessary to get Arizona’s share of the river’s water to the people in the Phoenix-Tucson corridor who needed it, but it came with a price. To get federal legislation needed to build it, Arizona had to agree to junior priority, standing behind California in the water line should supplies run short. That means that in theory California could dig in its legal heels and force Arizona to take huge cuts without losing a drop. You can see that importance of that historic sting in Arizona Department of Water Resources chief Tom Buschatzke’s op-ed on The Deal. It is crucial for Buschatzke to convince Arizonans on this point:

California would take reductions as well, but not before the lake has fallen to still lower levels. Current law states that California does not take reductions in deliveries until the Central Arizona Project completely dries up. Equity and fairness demand a different outcome.

California’s water leaders have made clear, often in private and increasingly in public, that they realize that brinksmanship, clinging to their 1968 politically won senior priority even as supplies to Phoenix are cut to zero, defies a sense of rightness and equity about sharing the river’s water. This echoes a point Brad Udall made in a series of talks in the summer of 2013 that had a significant impact on my thinking. It always seemed clear to me that any deal would inevitably require California to take cuts too. California agreeing to this in a formal, legally enforceable way, would be a huge deal.

What does California get in return?

In terms of what is now publicly known about the deal, what California gets is an agreement by Arizona and Nevada to take deeper cuts, sooner, than the current Lake Mead operating rules allow. Modeling runs implementing the terms of the deal suggest that may be enough. Under a set of dry years they call the “stress test”, there’s a 50-50 chance that with the additional Arizona and Nevada cuts Lake Mead will never drop low enough to require California to take its first tier of cuts. But the model also shows a worst case (a one in ten chance) under the stress test that California might have to take cuts as soon as 2019. (The “stress test” models a set of dry years with flows 16 percent below the long term median of the system’s historic performance, to give a feel for operations under climate change/drought conditions).

I have a bunch more thoughts and questions (blogger’s prerogative, it’s the end of the semester and I’m focused right now on helping our UNM Water Resources Program students). I’m especially curious about the current state of domestic politics among California water agencies, and also some of the more arcane terms of the deal, like what’s up with Intentionally Created Surplus below 1,075 under the agreement?

Delta smelt, culture wars icon

Fiorina told delegates at the state Republican Party convention here that protections for the threatened Delta smelt were a product of the “tyranny of the left, the tyranny of environmentalists.”

I fear discussions of the Delta smelt and environmental costs and benefits of moving California’s water from north to south have passed the point of useful discourse and into the realm of culture wars politics. (Quote from David Siders in the Sacramento Bee.)