The 2015 Drought so far – March 1

By Jay Lund

Droughts are strange, and this one is becoming scarier.

February began with a nice few stormy days, but has since looked like this January – very dry. And so far, the March forecast is not wet.

At the beginning of March, the Northern Sierra (Sacramento Valley) Precipitation Index was down to 88% of average to date, although it already almost equals total precipitation for all of 2014 (both good and bad news). For the San Joaquin Valley and Tulare basin (where most water use occurs), precipitation is about half of average for this date – slightly wetter than this time last year.  Snowpack is roughly like last year – among the driest on record.

Will March will be as dry?  Statistically, little can be said. There is little correlation in monthly precipitation during Northern California’s wet season, but droughts are inherently unusual.  The forecast and climate conditions so far look dry.

The best news is a bit more overall reservoir storage than last year at this time (but still about 5 maf below average for this time of year).   The big reservoirs in the Sacramento Valley have 1.3 maf more than last year at this time – this is the good news.  South of the Delta surface storage is about the same overall, but differently distributed.  San Luis reservoir, which serves the west side of the valley and southern California is about 600 taf higher, but the large reservoirs on the San Joaquin River tributaries are about 600 taf lower.

Groundwater storage is probably about 6 maf less than last year.

Without a miracle March, we will have another critically dry year for 2015.  Northern California is likely to be a bit better off than last year, but could be about the same (very dry).  In the southern Central Valley and southern California conditions could easily be as bad or worse than last year.

The state is likely to protect environmental flows more carefully this year, probably a good thing to reduce potential for more endangered species listings after the drought.  The State Water Project has said they expect about 15% deliveries.  The federal Central Valley Project has now announced initial 0% deliveries for regular agricultural water contracts, likely cutbacks (of 25%?) for water right exchange and settlement contractors, and 25% urban deliveries for 2015.  While these percentages might improve in the remaining month of the wet season, there is a good chance that water allocations will be similarly dismal to 2014, with less groundwater available in some parts of the state.

Reservoirs

Fortunately, some Northern California reservoirs have more storage than a year ago, while reservoir levels elsewhere are more mixed. Overall, we remain about 6 million acre-feet below average for reservoir storage this time of year.  In the southern Central Valley, west side reservoirs (San Luis) have much more water than last year, but the east side tributaries to the San Joaquin River are very low (Exchequer at 8% of capacity).

Aquifer levels will generally be lower than a year ago in the areas highly dependent on groundwater.

Source: California Department of Water Resources

Source: California Department of Water Resources

Snowpack

Snowpack is truly sad, about 16% of average for this time of year.

Precipitation

The 2014 water year ended at 60 percent of average annual precipitation for Sacramento Valley. For 2015, we’re already about at this total, so 2015 is very likely to be at least a bit wetter than 2014 for the Sacramento Valley.  A very wet March and early April sure would help.

<span style="color: #000000;">For updates, <a style="color: #000000;" href="http://cdec.water.ca.gov/cgi-progs/products/PLOT_ESI.pdf">click here</a>. <em>Source: California Department of Water Resources</em></span>

For updates, click here. Source: California Department of Water Resources

Both the San Joaquin and Tulare basins are slightly wetter than this time last year.  2015 could be better than 2014, but could also easily be drier.

Source: California Department of Water Resources

For updates, click here. Source: California Department of Water Resources

Source: California Department of Water Resources

For updates, click here. Tulare basin has a shorter record though it has the most water use in California. Source: California Department of Water Resources

The difference between a drought and a wet year in California is just a few storms. We are at two significant storms so far, mostly in the northern state.  There is little time left to make this up, particularly south of the Delta.

Sadly, our standard for 2015 is not  average, but  the miserable conditions of 2014.  That’s how dry it is.

Beware the dries of March.

Jay Lund is a professor of civil and environmental engineering and director of the Center for Watershed Sciences at UC Davis. 

Further Reading

The links above can help keep you up to date. For more data, explore the California Department of Water CDEC web site http://cdec.water.ca.gov.

Lund, J. The 2015 drought — so far. California WaterBlog. Jan. 5, 2015

Lund, J. and J. Mount. “Will California’s drought extend into 2015?California WaterBlog. June 15, 2014

Swain, D. “The Ridiculously Resilient Ridge Returns; typical winter conditions still nowhere to be found in CaliforniaCalifornia Weather Blog. Feb. 16, 2015

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Dutch lessons on levee design and prioritization for California

Dutch flood safety standards, established by economic risk analysis. Source: Flood Defence Act of 1996

Dutch flood safety standards, established by economic risk analysis. Source: Flood Defence Act of 1996

This is the second of an intermittent series of articles on the future of the Sacramento-San Joaquin Delta.

By Jay Lund

In any lowland, levees define how humans live and how they disrupt native habitats. This is as true for the Sacramento-San Joaquin Delta as it is for coastal Louisiana, Vietnam and the Netherlands.

Flood safety in the Delta is a statewide concern because the region serves as a hub for delivering water to most Californians and supports native fish.

Like many Dutch lowlands, the Delta became low from the conversion of tidal marsh to farmland. Once diked and drained, peat soils (accumulating over millennia with sea level rise) were exposed to air, decomposed and subsided. Dutch lowlands have sunk about 6 feet in 300 years, while some islands in the western and central Delta have subsided much more — up to about 25 feet over 150 years — because of California’s warmer and sunnier climate.

Administration of Dutch polders (islands)

The Dutch have a long and distinguished record of managing floods in their lowlands. They have been reclaiming dry land from the sea and marshlands since the Middle Ages. They have suffered and learned from centuries of flooding.

Local landowners did most of the land reclamation and paid for the work themselves. As the country grew, it consolidated the governance of reclamation from what were once thousands of local “water boards” to 24 regional boards, which maintain levees and dikes and treat wastewater.

Consolidation and growing prosperity brought more state involvement and funding for flood protection, along with more formal state protection standards and prioritization. Investments in flood protection are now guided by formal analyses of risks, costs and benefits (van Dantzig 1956).

Risk analysis

The Dutch risk analysis has provided a rigorous, understandable and widely accepted basis for flood management decisions and investments for nearly 60 years (Eijgenraam et al 2014, Schweckendiek 2013). The level of flood protection is chosen to minimize the total costs of flood damage and protect investments.

Using risk analysis to balance benefits and costs of flood protection (Schweckendiek 2013)

Using risk analysis to balance benefits and costs of flood protection Source: Schweckendiek 2013

Having risk analysis drive the setting of flood safety standards and investment priorities follows a long Dutch tradition of improving analytical tools to solidify the scientific basis of decision-making (Disco and van der Ende 2003).

The risk analysis has grown to include loss of life, longer planning horizons, sea level rise and more subtle aspects of levee system reliability – aspects that have led to better management of levees and floods (Eijgenraam et al. 2014, Jonkman et al 2011; Schweckendiek 2013).

The Dutch sometimes have retreated from the sea following catastrophic storms, or by design to increase flood conveyance capacity, restore natural areas and reduce costs. The Netherlands has setback some levees, widened some channels and “de-poldered” or abandoned some subsided land under its “Room for the River” program (van Staveren et al. 2014).

Implications for California’s Delta?

For the Delta, state levee decisions are probably the single most important and defining policy area. Living in the Delta and in lowlands elsewhere in the world is largely defined by the design and maintenance of levee systems and the prioritization of levee projects. The flow and mixing of water is shaped by the configuration and reliability of levee systems and how they fail. (In any system, levees will fail, and part of levee policy is what to do when they fail.) Levee systems also shape the remaining natural habitat for native species and other important habitat, such as the Delta’s famous bass fishery.

Where levee system design is so fundamentally important to so many interests, it is tempting to perform highly complex analysis of many alternative management strategies for each of the many social, economic and environmental interests in the region. However, thoughtful analysts and policymakers know such analyses can do more to confuse than enlighten.

The Dutch have brought three useful ideas to the design of their lowland levee system:

  • Define problems in ways they can be solved. The Dutch have defined their levee problem in a way that can be usefully solved, even if the definition is necessarily incomplete. Indecision or perpetuation of a deteriorating status quo is dangerous in lowlands. The Dutch begin by examining the economic benefits, costs and risks in levee system design. Economic sustainability and public safety are the major objectives for levees below sea level. Additional social and environmental concerns are considered separately. This process clarifies trade-offs and avoids more complex approaches that tend to add more confusion than insight.
  • Base levee standards and safety levels mainly on risk analysis. Economically and environmentally, some areas merit higher levels of flood protection than others. Some areas may deserve no flood protection at all. In other cases, flooding may benefit the environment.
  • Consolidate levee districts. Most levee maintenance is a local responsibility that is funded and inspected by the state. Long-term consolidation has resulted in more responsible use of state funds and better flood protection for more land.

California’s Delta has many unique challenges (Finch 1985; Lund et al 2010; Lund 2011), but much can be learned from the efforts and successes in the Netherlands (Woodall and Lund 2009; Ertsen and Lund 2011).

If we want to solve hard problems, we must define and organize them in ways that can be solved, even imperfectly. Indecision risks everything in lowlands – local lives and livelihoods, a water system serving millions of Californians and acres of farmland, and important habitat for native aquatic species. Nostalgia for the Delta of the 1950’s or 1850’s cannot prevail for long over the hard physics and economics of lowland risks.

Jay Lund is a professor of civil and environmental engineering and director of the Center for Watershed Sciences at UC Davis.

A note on Delta terminology

California has a long tradition of improperly naming physical features in the Sacramento-San Joaquin Delta, beginning with the term delta.

A river dike between Kesteren and Opheusden, the Netherlands, at high water levels oo the river Nederrijn in 1995. Photo by Henri Cormont/Wikimedia Commons

Throughout the rest of the world (with the exception of the Okavango Delta), deltas are formed where rivers disgorge into open bodies of water, leaving a prism of sediment shaped like the Greek letter Δ (delta)The Sacramento-San Joaquin “Delta” does not qualify as a traditional delta since it is formed at the tidally influenced confluence of two large floodplain rivers, which was submerged more than 6,000 years ago by sea level rise.

Other common misnomers are levees and islands. Levees are earthen embankments that hold back water during floods. The Delta “levees” are actually dikes because they hold back water all the time.

Islands are lands of positive relief surrounded by water. The Delta’s “islands” are reclaimed lands that form topographic depressions surrounded by water. In this regard, they are polders, not islands.

The Dutch, who have many dikes maintaining polders in their delta landscape, go by more authoritative terminology.

Further reading

Buijs, F.A., P.H.A.J.M. van Gelder, J.K. Vrijling & A.C.W.M. Vrouwenvelder, J.W. Hall, P.B. Sayers, M.J. Wehrung (2003), “Application of Dutch reliability-based flood defence design in the UK,” Safety and Reliability – Bedford & van Gelder (eds), Swets & Zeitlinger, Lisse, ISBN 90 5809 551 7

Disco, C. & J. van der Ende (2003), “Strong, Invincible Arguments?: Tidal models as management instruments in twentieth-century Dutch coastal engineering,” Technology and Culture, Vol. 44, July, pp. 502-535

Eijgenraam, C., J. Kind, C. Bak, R. Brekelmans, D.k den Hertog, M. Duits, K. Roos, P. Vermeer, W. Kuijken (2014), “Economically Efficient Standards to Protect the Netherlands Against Flooding,” Interfaces, Vol. 44, No. 1, January–February, pp. 7–21

Ertsen, M. and J. Lund, “Drowning Men Will Clutch at Straws – A Short Comparative History Of Dutch And Californian River Flood Management,” 25th ICID European Regional Conference Proceedings, Paper IV-5, 2011

Finch, M. (1985), “Earthquake Damage in the Sacramento-San Joaquin Delta, Sacramento and San Joaquin Counties,” California Geology.

Jonkman,S.N, R. Jongejan, and Bob Maaskant (2011),”The Use of Individual and Societal Risk Criteria Within the Dutch Flood Safety Policy—Nationwide Estimates of Societal Risk and Policy Applications,” Risk Analysis, Vol. 31, No. 2

Kind JM (2013) “Economically efficient flood protection standards for the Netherlands,” Journal of Flood Risk Management

Lund, J., E. Hanak, W. Fleenor, W. Bennett, R. Howitt, J. Mount, and P. Moyle, Comparing Futures for the Sacramento-San Joaquin Delta, University of California Press, Berkeley, CA, February 2010

Lund, J.R. (2011), “Sea level rise and Delta subsidence—the demise of subsided Delta islands,” California WaterBlog, posted March 9, 2011

Mostert, E. 2012. “Water management on the island of IJsselmonde 1000 to 1953: polycentric governance, adaptation, and petrification.” Ecology and Society 17(3): 12

Room for the River program

Schweckendiek, T. (2013), “Dutch approach to levee reliability and flood risk,” presentation to the National Research Council

Suddeth, R., J. Mount, and J. Lund (2010), “Levee decisions and sustainability for the Sacramento-San Joaquin Delta,” San Francisco Estuary and Watershed Science, Volume 8, No. 2, 23 pp

Suddeth, R. (2011), “Policy implications of permanently flooded islands in the Sacramento–San Joaquin Delta,” San Francisco Estuary and Watershed Science, 9(2)

van Dantzig, D. (1956), “Economic decision problems for flood prevention,” Econometrica 24(3):276–287

van Staveren, M.F., J.F. Warner, J.P.M. van Tatenhove, and P. Wester (2014), “Let’s bring in the floods: de-poldering in the Netherlands as a strategy for long-term delta survival?”, Water International, Vol. 39, No. 5, pp. 686-700

van der Vleuten, E. and C. Disco (2004), “Water Wizards: Reshaping wet nature and society.” History and Technology 20 (3), 291-309

Voortman, H.G. (2003), “Risk-based design of large-scale flood defence systems” PhD thesis, TU Delft, The Netherlands. Also published in the series “Communications on Hydraulic and Geotechnical Engineering” Delft University of Technology, Report no. 02-3

Voortman, H.G. and J.K. Vrijling (2004), “Optimal design of flood defence systems in a changing climate.” Heron, Vol. 49, No. 1

Vrijling, J.K., W. van Hengel, and R.J. Houben (199), “Acceptable risk as a basis for design.” Reliability Engineering and System Safety, 59:141-150

Walker, W. E., A. Abrahamse, J. Bolten, J.P. Kahan, O. Van De Riet, M. Kok, and M. Den Braber (1994), “A Policy Analysis of Dutch River Dike Improvements: Trading off Safety, Cost, and Environmental Impacts,” Operations Research, Vol. 42, No. 5

Woodall, D.L. and J.R. Lund (2009), “Dutch Flood Policy Innovations for California,” Journal of Contemporary Water Research and Education, Issue 141

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21st Century Delta: Reconciling the desired with the possible

The Sacramento - San Joaquin Delta, as seen from a ship traveling through the Stockton Ship Channel on September 24, 2013. Photo by Florence Lo, California Department of Water Resources

The Sacramento – San Joaquin Delta, as seen from a ship in the Stockton Deep Water Ship Channel in 2013. Photo by Florence Lo, California Department of Water Resources

This is this first in an intermittent series of articles on the future of the Sacramento-San Joaquin Delta.

By Steven Culberson

Estuaries are hard places to understand and even harder to explain. Estuarine scientists, myself included, have struggled to learn how changes in the San Francisco Estuary led to declining fish populations and waning productivity, particularly in the Sacramento-San Joaquin Delta.

We keep searching for what is broken or missing so we can fix or replace it. The thinking is that if we can return or repair these parts of the ecosystem, native aquatic species will recover sufficiently to be resilient in the future.

The trouble is we can’t go back to the way things were more than 150 years ago, before engineers repurposed the Delta’s maze of marshy islands, channels and sloughs for agriculture and water delivery. As fish biologist Peter Moyle has said, “How do you bring back tule or cattail marsh to an island that has sunk 30 feet from decades of farming its peaty soil? You can’t.”

Likewise, fixing what is broken in the Delta has been a daunting if not quixotic pursuit. Scientists for the most part take the classic “reductionist” approach of breaking down complex problems into smaller and simpler units: (1) Identify the ecological features that are damaged or in short or excess supply, (2) pinpoint factors responsible for these problems, then (3) take steps to improve conditions factor by factor or species by species.

This painstaking process has unquestionably improved our understanding of how the Estuary works. But for all the reams of studies produced over the past 30 years we have yet to arrest, let alone reverse, the ongoing decline in pelagic fish populations and ecological health of the Delta.

I propose an alternative but complimentary “reconciliation” approach to restoring the Delta:

  • Reconcile what we would like to have the Delta be like with what is possible, using our understanding of the historical landscape and its remnant physical features as design guides.
  • Focus on returning the physical features where ecological processes occur — islands, marshes, deep areas, shoals, shallows, littoral edges, eroding streambeds and riparian corridors — without necessarily worrying about identifying or understanding the precise effect these actions will have on the species of concern.
  • Put mud flats where mud flats would go, tidal marshes where tidal marshes have been and are likely to endure. Put open water next to shallows.
  • Work with alien species as part of new, unprecedented estuarine ecosystems.

Return estuary-like features to the estuary and the natural arrangements between geomorphic elements and habitat will re-establish and re-configure themselves. Ecosystems are, after all, self-regulating and self-organizing, even as they change through time. Systems ecologists have struggled to teach us this and we should be willing to learn, given our relative lack of restoration success in the estuary (see Jorgensen 2012).

Creating habitat interfaces or “edges” like those visible in the photograph below would be a good start on fixing our estuarine system.

In Sherman Lake, just north of Antioch

Sediments emerging on ebb tide from submerged vegetation in the Sacramento-San Joaquin Delta. The strip of non-native vegetation here in Sherman Lake, just north of Antioch, traps sediment when plentiful and releases it back into the water column over time. Re-introducing geomorphically active sites like this will help return some ecological dynamism to support desired species, native and alien. Source: Google Earth

We need to make choices and invest resources in the absence of perfect knowledge of the ecosystems being managed. This doesn’t mean we dispense with scientific rigor or altogether abandon the reductionist or species-based investigations. Rather, we should view the estuary more as a system than an assembly of parts and let the ecosystem itself sort out the particulars.

We cannot afford to wait until we’re sure about what will work. Because the pace of rigorous science proceeds slowly we’re unlikely to gain sufficient additional understanding about estuary functions over the next decade to make bold, large-scale changes in management. Yet the demands for a better functioning Delta ecosystem exist now.

It’s questionable whether we can even predict the total outcome of our restoration actions in a changing self-regulated system. Species in ecosystems as complex as estuaries can change roles in unexpected ways, like switching from one prey to another or shifting habitat use in response to a competitor.

We must take the ecological gamble. Provide the types of flows, landscapes and habitat mix we already know make for a better functioning ecosystem. Stand back and let the Bay-Delta reorganize itself the way estuaries do – and learn to live with the outcome.

Steven Culberson is a senior ecologist with the U.S. Fish and Wildlife Service in Sacramento. “The findings and conclusions in this article are those of the author(s) and do not necessarily represent the views of the U.S. Fish and Wildlife Service (117 FW 1)”

Further reading

Jorgensen, S.E. 2012. Introduction to Systems Ecology. CRC Press. 360pp.

Moyle, Peter. “Ten realities for managing the Delta.” California WaterBlog. Feb. 26, 2013

Rosenzweig, M.L. 2003. “Win-Win Ecology: How the Earth’s Species Can Survive in the Midst Of Human Enterprise. Oxford University Press, 209 pp.

 

 

 

 

 

 

 

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The romance of rain barrels

Photo By Bo Peng, UC Davis

A Davis, Calif. home advertises its rainwater collection system. Photo by Bo Peng, UC Davis

By Jay Lund

Imagine capturing some of the heavy rain that has been draining off Northern California roofs lately to water yards this summer, for what will likely be a fourth year of drought.

The drought has generated interest in household cisterns commonly known as “rain barrels” that collect and store rooftop runoff for when it is most needed – during the dry season – to irrigate landscapes and replenish community groundwater supplies. Advocates of these rainwater collectors point to their prevalence in Australia following its decade-long Millennium Drought.

But how cost-effective are rain barrels for individual home and business owners, compared with the more communal approach of adding storage capacity behind a dam upstream?

Here are some back-of-the-envelope calculations:

The cost of household cisterns includes the storage tank, installation and connection to a roof, maintenance and the value of land for the cistern’s footprint. A 50-gallon rain barrel costs about $100, and a 300-gallon tank runs about $600.

The cost of the storage tank or barrel alone amounts to $652,000 an acre-foot of storage capacity (summed over many households). This compares with about $2,000 an acre-foot for expanding storage capacity at large upstream dams.

But storage capacity for water supply is useful only to the extent water is available to capture. Most recent proposals for expanding upstream reservoirs in California yield annual water deliveries of only 5 to 20 percent of the additional storage capacity. In California’s climate, the additional storage space can refill only every few years, implying water delivery costs of $500 to $2,000 per acre-foot of water delivered (annualizing the initial cost at a 5 percent interest rate).

2015-02-08 05.35.30

“This site is now collecting rainwater” boasts this Davis, Calif. home. A set of 50-gallon rainwater barrels is connected to a downspout. Photo by Chris Bowman

Rainwater cisterns in California might be drained several times during the wet season to replenish groundwater or even out stormwater flows, and once or twice during the spring for landscape irrigation.

For a typical home in coastal California, the annual pattern of storms might allow filling and emptying a 50-gallon cistern one to three times (with considerable overflow possible each time), yielding 50 to 150 gallons a year – less than 0.1 percent of a household’s annual water use in California. For inland homes, the actual water produced would be much less because the rain barrel is capturing runoff that likely would have been used by others downstream anyway.

Indeed, if a rain barrel’s installation removes 8 square feet of a highly watered lawn (1 to 2 acre-feet a year), the gallons saved from reducing the irrigated area would be similar to the water provided by the rain barrel.

So the cost of water supplied by household cisterns in California for landscape irrigation or groundwater recharge could be $11,000 to $32,600 an acre-foot. This is 10 to 20 times the wholesale cost of water in Southern California and 5 to 10 times the cost of desalinating seawater.

While the economics of household cisterns for water supply in California are unattractive, cistern collection systems do provide some environmental benefits. Evening out stormwater flows reduces the costs of managing it downstream. And the prominent display of rain barrels at homes and businesses serves as a constant reminder of the scarcity of water in California, perhaps increasing water conservation more generally.

Jay Lund is a professor of civil and environmental engineering and director of the Center for Watershed Sciences at UC Davis.

Further reading

Portland’s Regional Water Providers Consortium has a nice primer on rain barrels

American Rainwater Catchment Systems Association has a large collection of additional information.

San Diego posts a Rainwater Harvesting Guide for homeowners.

Alliance for Water Efficiency provides an overview on the history and effectiveness of rain barrels and other useful resources, including:

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Rain or shine, California drought still kicking

Source: National Weather Service

California’s drought is still very much alive, despite all appearances from this Feb. 4 – 9 precipitation forecast. Source: National Weather Service

green-audio-iconFeb. 4, 2015 drought update on Capital Public Radio


By Jay Lund

Odds are exceedingly good that February will top January’s contribution to precipitation in California. It’s hard to be drier than what was essentially zero rain and snowfall last month.

The state’s driest January on record dropped the Northern Sierra Precipitation Index down from 145 percent of average at the end of stormy December to 84 percent of average today, Feb. 4. And this is for California’s wettest region, the Sacramento Valley. For the San Joaquin Valley and Tulare basin (where most water use occurs), precipitation is, respectively,  43 percent and 45 percent of average for this date.

What does this mean for the usually wet months of February and March?

Statistically, not much can be said. There is little correlation in monthly precipitation during Northern California’s wet season. But droughts by nature are exceptional, so we should prepare for yet a fourth straight year of exceptionally dry conditions.

Summary of conditions statewide

Despite December’s storms, California’s drought remains very much alive. The heavy rain forecast for Northern California this weekend won’t wash it away.

We are halfway through the wet season and our reservoirs overall are holding little more than they did a year ago. Our aquifers are holding less. The snowpack is 25 percent of average and precipitation statewide is well below average for this time of year. Native fish are worse off in many areas.

A drought worse than last year’s whopper is unlikely but remains a possibility, especially for the southern Central Valley.

We still can’t say much for sure about the 2015 water outlook until March. But with only two months left in the wet season, continued drought seems likely.

Reservoirs

Fortunately, many Northern California reservoirs have more storage than they did a year ago, while reservoir levels elsewhere are more mixed. Overall, we remain about 6 million acre-feet below average for reservoir storage this time of year.

Aquifer levels are slowly rising but still probably much lower than they were a year ago in the areas highly dependent on groundwater.

Source

For updates, click here..  For more detailed data on other reservoirs, click hereSource: California Department of Water Resources

Snowpack

Snowpack is sparse throughout the Sierra Nevada, about 25% of average for this time of year.

February2015snowpack

http://cdec.water.ca.gov/cdecapp/snowapp/sweq.action

http://cdec.water.ca.gov/cgi-progs/snow/PLOT_SWC

Precipitation

Last year ended at 60 percent of average annual precipitation for Sacramento Valley. For 2015, we’re already at about 50 percent, thanks to a wet December. It seems unlikely this year will be drier than last, but it could happen if February and March are a bust.

For updates, click here. Source: California Department of Water Resources
For updates, click here. Source: California Department of Water Resources

So far, both the San Joaquin Valley and Tulare basin are wetter than this time last year, but not by much.

For updates, click here. Source: California Department of Water Resources

For updates, click here. Source: California Department of Water Resources

For updates, click here. Source: California Department of Water Resources

For updates, click here.  Tulare basin has a shorter record though it has the most water use in California. Source: California Department of Water Resources

Remember, the difference between a drought and a wet year in California is just a few storms. We still have months to go.

Further Reading

The links above can help keep you up to date. For more data, you might enjoy poking around the California Department of Water CDEC web site http://cdec.water.ca.gov. Some statistical views of drought and El Nino in California can be found in the further readings below.

Lund, J. The 2015 drought — so far. California WaterBlog. Jan. 5, 2015

Lund, J. and J. Mount. “Will California’s drought extend into 2015?California WaterBlog. June 15, 2014

Schonher, T. and S. E. Nicholson (1989), “The Relationship between California Rainfall and ENSO Events,” Journal of Climate, Vol. 2, Nov. pp. 1258-1269

Swain, D. “An exceptionally dry January…once again.” California Weather Blog. Feb. 1, 2015

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How dam operators can breathe more life into rivers

Folsom Dam and lake full of water. Photo by Paul Harnes, California Department of Water Resources

Folsom Dam and lake full of water. Photo by Paul Harnes, California Department of Water Resources

By Sarah Yarnell

Dams are no friend to biodiversity. Once impounded, a river answers first and foremost to human needs, be it water supply, energy production or flood protection. Releases are measured and timed to satisfy these demands.

As a result, the river downstream loses much of its natural variability in timing, volume and spread of flows. Dams also block passage of sediment that scours the stream channel and deposits fresh cobble bars. These activities create and maintain habitats for multiple species, contributing to biodiversity.

But dams don’t have to be death knells of biodiversity. Operators can manipulate flows in ways that restore some of their ecological functions that promote diverse riverine animal, plant and fish communities.

Releasing flows for environmental purposes is not new. California has long required dam owners to release enough flow “at all times” to keep fish “in good condition.” Further, some water and power suppliers are required under the federal Endangered Species Act to release flows at biologically important times for imperiled native fish.

These “environmental flows,” as water managers call them, may help fish survive, but they do not necessarily create habitat that promote high biodiversity. For that you need to implement a suite of well-timed flow patterns that move sediment and can access floodplains and over-bank areas.

My research colleagues and I recently identified five types of flows that are key to creating multiple habitats. We presented them recently at the annual meeting of the American Geophysical Union in San Francisco.

We call these “functional flows,” as distinct from fish-saving “environmental” ones, because they provide certain geomorphic, ecological or biochemical functions that support breeding, migration, habitat diversity and, ultimately, biodiversity.

We build on a term originally coined by Escobar-Arias & Pasternack in 2010 and define a functional flow as a component of the hydrograph that provides a distinct geomorphic, ecological or biogeochemical function. Physical processes and biotic interactions in rivers operate in three dimensions—longitudinally, laterally and vertically—and are intimately tied to the timing, duration and frequency of natural flows, so functional flows must also be reflective of the natural patterns that occur in both space and time. We illustrate the approach in med-montane systems with a distinct high and low flow seasonality, such as mixed rain-snow Sierra hydrograph shown here.  These systems are highly sensitive to hydrological change, exhibiting relatively short relaxation times to flow regulation. A functional flows approach would retain particular components of the hydrograph that provide ecogeomorphic functions.  Here we emphasize 5 flow components that should be retained.

This hydrograph shows the typical natural and “functional flow” patterns of  rivers in the Sierra Nevada and five components that provide distinct geomorphic, ecological or biogeochemical functions that help create and maintain habitat for multiple native species. Source: UC Davis Center for Watershed Sciences

Five functional flow patterns key to creating and maintaining habitat for multiple species:

1.  Wet season initiation flow

  • Clears riverbed of organics, fine sediment
  • Reconnects stream with riparian and over-bank areas
  • Kick starts nutrient cycling
  • Provides ecological cues for native species such as the delta smelt to migrate upstream

In many river systems, these actions can be accomplished simply by letting the first major, sediment-loaded storm runoff of the season – known as the “first flush” – pass through dams.

2.  Peak flow

Flooded oaks on Cosumnes River. Photo: UC Davis

Flooded oaks on the Cosumnes River south of Sacramento. Photo: UC Davis

  • Timed to coincide with the natural season of high flows and floods, ideally during big storms and other correlative weather conditions that native fish may respond to
  • Should last long enough to scour out pools, form channel bars, activate floodplains and otherwise create diverse habitat
  • Redistributes large amounts of sediment, creating geomorphic diversity
  • Reduces extent of exotic species that are not adapted to these disturbances
  • Keeps vegetation from encroaching on stream channels
  • Resets the natural process of ecological succession

Water spilled from flooded reservoirs also is good for moving sediment. But these events happen only once every five to ten years. The annual peak flow helps maintain the form and structure of river channels, however these flows are often captured behind dams rather than passed downstream.

The free-flowing nature of the Cosumnes River allows frequent and regular winter and spring flooding that fosters growth of native vegetation and wildlife.

The free-flowing Cosumnes River south of Sacramento regularly floods during the wet season, promoting growth of native fish. UC Davis researchers Carson Jeffres (left) and Eric Holmes capture, measure and identified fish that took advantage of the flooding in December 2012. Photo: UC Davis

3.  Spring recession flow

Source

California’s rare foothill yellow-legged frog breeds only in rivers and streams and lays its eggs in clusters that attach to submerged rocks. Photo by Ryan Peek, UC Davis

  • Timed to coincide with the springtime transition between high and low flows
  • Mimics the natural rate of decline in snowmelt flows, which is gradual
  • Provides distinct annual cues for native aquatic species to reproduce and out-migrate
  • Should last long enough to sustain habitats that species need to successfully reproduce and to redistribute sediment throughout the stream

As dam operators in the Sierra Nevada fill reservoirs, river levels can drop sharply, from the peak spring flows spilling over dams to the low, flat-lined summer flows. Gradually ramping down the spill flows can provide the in-stream conditions needed for survival of native species, such as the rare foothill yellow-legged frog, whose submerged eggs could get stranded and left to bake in the sun.

4.  Dry season low flow

  • Timed to occur during the warmest and driest part of the year (typically September in California)
  • Should be low enough to disconnect the stream from its floodplains, to create a variety of ecological niches that promote a medley of riparian plants and trees
  • Should maintain the natural ephemeral or perennial conditions

Releasing artificially high base flows often benefits non-native species that are not adapted to the biologically stressful low-flow periods.

5.  Inter-annual flow variability

  • Mimics the natural variability between years in magnitude, timing and duration of specific flow events
  • Supports diversity in habitat and native species over the long term

Bigger, longer floods should be planned for years when water is plentiful, while smaller, shorter peak flows should occur in drier years.

Dam operators need to bring greater sophistication into the design and implementation of flows for multiple uses, including ecosystem services, water supply and flood control.

To maximize the limited allocations of water for ecosystem purposes, the focus of discussions should shift from flow volume to “functional flows” that support natural disturbances, promote certain physical dynamics and drive ecosystem functions.

When geomorphology and sediment processes are considered with flow magnitude, timing and duration, the creation and maintenance of habitats for multiple species can be sustained, and biodiversity is supported. A functional flows approach provides the best opportunity to encompass these ecosystem processes alongside human needs.

Sarah Yarnell is a senior researcher with the UC Davis Center for Watershed Sciences. 

Further reading

Arthington AH. 2012. “Environmental flows: Saving rivers in the third millennium.” University of California Press

Beechie TJ, Sear DA, Olden JD, Pess GR, Buffington JM, Moir H, Roni P, Pollock MM. 2010. “Process-based principles for restoring river ecosystems.” Bioscience 60:209-222

Escobar-Arias, M. I. and G. B. Pasternack (2010). “A hydrogeomorphic dynamics approach to assess in-stream ecological functionality using the functional flows model, Part 1- Model Characteristics.” River Research and Applications 26(9): 1103-1128

Greco SE, Larsen EW. 2014. “Ecological design of multifunctional open channels for flood control and conservation planning.” Landscape and Urban Planning 131:14-26

Kiernan JD, Moyle PB, Crain PK. 2012. “Restoring native fish assemblages to a regulated California stream using the natural flow regime concept.” Ecological Applications 22:1472-1482

Lund JR, Moyle PB. “Is shorting fish of water during drought good for water users?California WaterBlog, June 3, 2014

Moyle PB, Mount JF. 2007. “Homogenous rivers, homogenous faunas.” Proceedings of the National Academy of Sciences of the United States of America 104:5711-5712

Petts GE. 1996. “Water allocation to protect river ecosystem.” Regulated Rivers-Research & Management 12:353-365

Suddeth, Robyn. “Reconciling fish and fowl with farms and flooding.” California WaterBlog. Dec. 2, 2014

Wohl E. 2012. “Identifying and mitigating dam-induced declines in river health: Three case studies from the western United States.” International Journal of Sediment Research 27:271-287

Yarnell, Sarah. “Life springs in Sierra rivers and springtime flows recede.” California WaterBlog, May 4, 2013

Yarnell, Sarah. “Sierra frogs breed insights on river management.” California WaterBlog, Oct. 3, 2012

Yarnell SM, Viers JH, Mount JF. 2010. “Ecology and management of the spring snowmelt recession.” Bioscience 60:114-127

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Demystifying mist as a source of water supply

Source: Wikicommons

Fog envelopes the Golden Gate Bridge. Source: Wikimedia Commons

By Jay Lund

In some of the world’s driest places, atmospheric moisture is a major source of water for native ecosystems. Some algae, plants and insects in the Israeli and Namibian deserts get much of their water from fog, dew and humidity. The spines of some cacti species have evolved to collect fog droplets. California’s redwood forests derive a significant amount of their moisture from fog.

Some drought-minded California residents along the coast, perhaps yearning for a clear ocean view, have suggested harvesting fog as a water supply.

Globally, few places get drinking water from coastal fog. They are mostly rural areas with abundant fog but little other available water. Communities along the parched northern coast of Chile have captured fog for some of its water supply by erecting large fences of synthetic fiber cross-wise to the coastal wind. The condensate on the netting is channelled for collection and use.

Source

A fog fence or catcher supplies water to poor residents of Lima, Peru. Source: Wikimedia Commons

Fog harvesting yields from 1 quart to 3 gallons of water daily per square yard of fog mesh [1].

What would this mean for a typical coastal household?

A household of three that uses 300 gallons a day would need 1,030 to 12,300 square feet of fog mesh [2]. To fit on a typical single-family lot,  the length of the fog fence would be limited to about 50 feet. That means the fence would need to stand 21 to 250 feet tall, about the height of the State Capitol dome.

To fit on a typical single-family lot, the length of the fog fence would be limited to about 50 feet. That means the fence would need to stand 21 to 250 feet tall, about the height of the State Capitol dome. Illustration by Stephanie Pi, UC Davis.

To fit on a typical single-family lot, the length of the fog fence would be limited to about 50 feet. That means the fence would need to stand 21 to 250 feet tall, about the height of the State Capitol dome. Illustration by Stephanie Pi, UC Davis.

Building such a fence would cost a household thousands of dollars and require cleaning (algae tends to grow on the mesh) and repair (the mesh becomes a big sail in a storm). Homeowners probably also would want a sizable water tank to fill for periods of clear weather.

For virtually all homeowners, a fog water supply would almost always be costly and inconvenient. Some households might use fog as a supplemental supply, but it usually will be at a steep additional cost.

If these numbers were scaled up for San Francisco, population 800,000, the fog fence would need to cover 10 to 120 square miles, or 20 percent to 2.5 times the area of the city (47 square miles). Fog will unlikely be a major water supply for California.

But this is only for atmospheric fog. More petty forms of fog frequently blur discussions of water in California. If we could demistify some of this haze, we might condense our discussions and diminish our droughts.

Jay Lund is a professor of civil and environmental engineering and director of the Center for Watershed Sciences at UC Davis.


[1] The density of liquid water is 1,000 kg per cubic meter. The density of water in fog might range from 0.05 to 0.5 grams per cubic meter. If the fog mesh can wring 10 to 50 percent of the water from a coastal breeze blowing 2 miles per hour for half the day, then 1 cubic meter of fog mesh would produce roughly 1 cup to 2.5 gallons of water a day. Not a bad agreement between theory and practice.

[2] To meet a daily water demand of 300 gallons, the coastal household would need a giant square fog mesh of 32 to 111 feet on each side for a total area of 1,030 to 12,300 square feet, which is larger than most California houses.

Further reading

Dawson, T. E. (1998), “Fog in the California redwood forest: ecosystem inputs and use by plants,” Oecologia, Volume 117, Issue 4, December, pp 476-485

Estrela, M.J., J.A. Valiente, D. Corell, M.M. Millán. 2008. “Fog collection in the western Mediterranean basin (Valencia region, Spain)”. Atmospheric Research, Volume 87, pp. 324–337

Friedmann, I., Y. Lipkin, and R. Ocampo-Paus. 1967. “Desert Algae of the Negev (Israel)”. Phycologia, 6:4, 185-200

Goodman, J. 1985. “The collection of fog drip”. Water Resources Research, Vol. 21, No. 3, pp. 392-394. A very small field experiment on coastal Montara Mountain south of San Francisco, Calif.

Henschel, J.R. and M.K. Seely. 2008. “Ecophysiology of atmospheric moisture in the Namib Desert”. Atmospheric Research, Volume 87, Issues 3–4, March 2008, Pages 362–368

Ju, J., H. Bai, Y. Zheng, T. Zhao, R. Fang, and L. Jiang. 2012. “A multi-structural and multi-functional integrated fog collection system in cactus”. Nature Communications, 4 Dec. 2012

Klemm, O. et al. 2012. “Fog as a Fresh-Water Resource: Overview and Perspectives”. Ambio. Mar 2012; 41(3): 221–234

Snyder, R.L. 1992. “Fog contribution to crop water use”. Drought tips, No. 92-40, UC Davis

Victoria, M. and M. Jaen. 2002. “Fog water collection in a rural park in the Canary Islands (Spain)”. Atmospheric Research, Volume 64, pp. 239–250

 

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A salmon success story during the California drought

Salmon spawning in Shasta River. Photo by Carson Jeffres, UC Davis

Salmon spawning in Shasta River. Photo by Carson Jeffres, UC Davis

Looking back on 2014, it’s hard not to feel despair for California salmon.

With drought-stricken rivers running dangerously warm and slow for spring migration, the government was giving millions of young hatchery salmon a lift to the Pacific by truck and barge. Come August, several streams in the Central Valley were drying up. Native fish were absent from many of their summer haunts.

There was, however, a startling exception to the run of bad salmon news.

On the Shasta River, a lifeline for Siskiyou County cattle ranchers, more than 18,000 fall-run Chinook salmon returned from the ocean. That’s more than double the return from the previous fall. More importantly, average returns during the past four years have quadrupled.

No one knows for sure why salmon are surging in the Shasta; many factors affect salmon population dynamics. However, one of those factors — the condition of freshwater habitats — dramatically improved following the exclusion of cattle from a spring-fed tributary, Big Springs Creek.

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The 2.2 mile Big Springs Creek (center) is fed from the snow-capped Mount Shasta. The snowmelt runs underground through porous volcanic rock before eventually bubbling up in the creek. The Shasta Basin (outlined) is part of the much larger Klamath Basin (inset). Source: UC Davis Center for Watershed Sciences

Historically, the creek had been a poster child for salmon habitat. Its water originates from springs fed from the snow-capped Mount Shasta, elevation 14,162 feet. As snow melts, it flows underground through porous volcanic rock, rather than running off in streams. Water eventually bubbles up, forming the creek, at about 55 degrees (12 degrees C) — just right for salmon and steelhead trout.

Enriched with nitrogen and phosphorous from volcanic and sedimentary rock, the spring water nourishes an abundance of aquatic plants that teem with insects. The plants provide good cover from fish-eating birds and a respite from high-velocity currents. Fish can eat bugs at their leisure. They grow exceptionally fast and big, increasing their chances of survival when they leave for the ocean and return to the creek to spawn.

All 2.2 miles of Big Springs Creek flows through a cattle ranch that has been operating for more than 100 years. During that time, the luxurious habitat gradually deteriorated. Cows trampled banks and spawning beds and stripped streamside vegetation. They devoured the aquatic plants, making the creek shallower and inhospitably warm in the summer.

The Nature Conservancy had long eyed the Shasta Basin because of its potential to provide high quality habitat for native salmon and steelhead — particularly coho salmon, which are federally designated as “threatened” with extinction. Historically, the 60-mile-long Shasta River was one of the most productive salmon streams in California. As a tributary to the Klamath River, the Shasta contributed only 1 percent of the flow but supported 50 percent of the Chinook salmon (NRCS 2004).

Counts of adult Chinook salmon returning to three tributaries of the Klamath River. Data provided by California Department of Fish and Wildlife

Counts of adult Chinook salmon returning to three tributaries of the Klamath River. Data provided by California Department of Fish and Wildlife

Little was known about the ecology and hydrology of the Shasta River because nearly all of the watershed is privately owned. But a research opportunity arose after the Nature Conservancy bought the 1,700-acre Nelson Ranch, in 2005. The U.S. Bureau of Reclamation, a Klamath Basin dams operator obligated to protect imperiled fish, commissioned the UC Davis Center for Watershed Sciences and Watercourse Engineering Inc. to do a baseline assessment of conditions for salmon and steelhead.

The study confirmed that the river through Nelson Ranch “provides unique and potentially very high quality habitat for rearing juvenile salmonids,” but found the water too warm in the spring and summer for young coho (Jeffres et al. 2007).

Significantly, the 2007 report suggested that temperatures could be improved by repairing Big Spring Creek, just upstream of Nelson Ranch. Researchers found that the creek contributes most of the Shasta’s summertime flow and strongly influences its temperatures for as much as 14 miles downstream (Nichols et al. 2014).

Two years later, in 2009, the Nature Conservancy bought all but 407 acres of the 4,543-acre Shasta Big Springs Ranch along the creek. The organization leased the pastures so ranching could continue, but fenced the entire stream.

Photos by Carson Jeffres, UC Davis

Big Springs Creek in 2008, the year before fencing (left), and six months after cattle exclusion. Photos by Carson Jeffres, UC Davis

Results of the cattle exclusion were dramatic.

In just the first year, the creek transformed from wide, turbid and shallow to cool, clear and deep. Without the constant grazing, the aquatic plants began to grow back, providing shade, protective fish cover and insect habitat. As of last fall, just five years later, annual maximum water temperatures had declined by as much as 7 degrees (4 degrees C) – a substantial and rapid improvement.

Sources: UC Davis Center for Watershed Sciences, Watercourse Engineering Inc.

Annual maximum temperatures at the mouth of  Big Springs Creek. The stream was fenced off to cattle in 2009. Sources: UC Davis Center for Watershed Sciences, Watercourse Engineering Inc.

Likewise, the extent of suitable, connected salmon and steelhead habitat has increased dramatically throughout the creek — and for miles downstream in the Shasta River. Young coho are now seen at several sites in the creek and river, compared with surveys of 2008, when they were observed only in a single pool at the creek’s headwaters.

 

Video of Chinook salmon in Big Springs Creek by Carson Jeffres, UC Davis, 2012

Time and ongoing research will tell what the recovery of Big Springs Creek means for recovery of Shasta Basin salmon and steelhead. But the huge increase in suitable habitat provides a remarkable benefit for all species that need high quality waters.

The Shasta Basin strategy has useful implications for stream recovery efforts elsewhere. While it’s tempting to focus on the livestock fencing as the solution, three cornerstones laid the foundation for success:

  • An earnest and transparent scientific process to identify ecologically high-value sites and key limiting factors
  • Acceptance of the scientific process, with its uncertain timelines and outcomes, by recovery project funders and interest groups
  • Commitment to implement a solution that maintains the economic well-being of riverside landowners – in this case, cattle ranchers.

Together, these elements paved the way for scientific discovery, both in identifying the major ecological impairments and determining how to address them.

Source: UC Davis Center for Watershed Sciences

Government agencies and nonprofit groups whose management affects salmon and steelhead in the Shasta Basin. Source: UC Davis Center for Watershed Sciences

With habitat recovery in Shasta Basin now underway, other basin landowners can help sustain it. Salmon restoration efforts in the region already enjoy broad support and collaboration among public, private and non-profit entities. Several measures are already established, including controls on irrigation runoff, removal of barriers to fish passage and water transactions that increase streamflows for fish at biologically important times.

Conservation activities at the basin scale are necessary to develop and maintain salmon and steelhead habitat. However, certain ecologically important river reaches are paramount to successful recovery. Good stewardship of these critical reaches leverages the value of all conservation efforts in the basin.

Ann Willis, an engineer and research coordinator with the UC Davis Center for Watershed Sciences, wrote this article with contributions from the center’s Peter Moyle, professor of fish biology, and Michael Deas, president of Watercourse Engineering Inc. of Davis. Center researchers Robert Lusardi, Carson Jeffres and Andrew Nichols also contributed. 

Further reading

Jeffres CA, Dahlgren RA, Kiernan JD, King AM, Lusardi RA, Nichols AL, Null SE, Tanaka SK, Willis AD, Mount JD, Moyle PB, Deas ML. 2009. Baseline Assessment of Physical and Biological Conditions Within Waterways on Big Springs Ranch, Siskiyou County, California. Center for Watershed Sciences, UC Davis

Jeffres CA, Mount JF, Moyle PB, Deas ML, Buckland E, Hammock B, Kiernan JD, King AM, Krigbaum N, Nichols AL, Null SE. 2007. Baseline Assessment of Salmonid Habitat and Aquatic Ecology of the Nelson Ranch, Shasta River, California Water Year 2007. Center for Watershed Sciences, UC Davis

Lusardi RA and Willis AD. 2014. Aquatic plants: unsung but prime salmon habitat. California WaterBlog

Lusardi RA. 2013. How to save salmon: Location, location, location. California WaterBlog

National Research Council (NRC). 2004. Endangered and Threatened Fishes in the Klamath River Basin: Causes of Decline and Strategies for Recovery

Nichols AL, Willis AD, Jeffres CA, Deas ML. 2014. Water Temperature Patterns Below Large Groundwater Springs: Management Implications for Coho Salmon in the Shasta River, California. River Research and Applications, vol. 30 (4)

Willis AD, Nichols AL, Jeffres CA, Deas ML. 2013. Water Resources Management Planning: Conceptual Framework and Case Study of the Shasta Basin. Center for Watershed Sciences, UC Davis

Willis AD, Deas ML, Jeffres CA, Mount JF, Moyle PB, Nichols AL. 2011. Executive Analysis of Restoration Actions in Big Springs Creek March 2008-September 2011. Center for Watershed Sciences, UC Davis

U.S. Environmental Protection Agency. 2003. EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards

 

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The 2015 drought – so far, January

Source: Wikimedia Commons

Rain gauge. Source: Wikimedia Commons

By Jay Lund

The California Department of Water Resources does a great job assembling data that can give insights on water conditions during the ongoing drought. They update the information daily (which can be addictive for some of us) on the California Data Exchange Center website.

Here are highlights of water conditions as of January 4:

Summary

A drought as bad as last year seems unlikely, but remains a possibility, especially for the Tulare Basin in the southern Central Valley. Rain has arrived, but the drought has not yet left. Fortunately, we have three months left in the wet season. We won’t know much for sure about the 2015 water outlook until March, no matter how eager we want to know. For the Sacramento and San Joaquin valleys, El Nino — the periodic shift of warm water from the Western to the Eastern Pacific — is a poor predictor of runoff in northern and central California.

Reservoirs

The December storms helped, but surface water storage remains about 5 million acre feet below average for this time of year. The Sacramento area is in much better shape, but most other areas are worse off or about the same in terms of storage than a year ago.

Source: California Department of Water Resources

Source: California Department of Water Resources

Further information:
– http://cdec.water.ca.gov/cgi-progs/products/rescond.pdf
– http://cdec.water.ca.gov/cgi-progs/reservoirs/RES

Snowpack

The snowpack overall remains about 50 percent of average for early January. Hopefully we will have a decent skiing season.

Source: California Department of Water Resources

Source: California Department of Water Resources

Further information:
-http://cdec.water.ca.gov/cdecapp/snowapp/sweq.action
-http://cdec.water.ca.gov/cgi-progs/snow/PLOT_SWC

Precipitation

Among the most useful DWR data are the daily precipitation indices for the Sacramento Valley, San Joaquin Valley and Tulare Basin.

The Sacramento Valley is at 121 percent of average for early January (its meager snowpack notwithstanding), so it would be extraordinary for the region to end up drier this year than in 2014.

The San Joaquin Valley and Tulare Basin are not accumulating precipitation as fast, with 65 percent and 67 percent of average precipitation respectively for this time of year. At this point, part way through the wet season, it seems plausible — though unlikely — that this year will be as dry as the last in these areas.

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Source: Tulare Basin Precipitation Index, DWR. The record on the Tulare Basin appears to be shorter, though this region uses more water than any other part of California.

I hope DWR eventually will add a precipitation index for southern coastal California (south of the Tehachapis) and some indices of water storage in major groundwater basins, where most of California’s water storage resides.

These precipitation indices are telling, particularly the more recent yearly plot lines. Those have daily data so you to see how much each storm contributed to the annual water supply. Such close tracking shows that the difference between a drought and a wet year in California can be due to 3-5 storms, the size of these individual storms, and where these storms hit.

Jay Lund is a professor of civil and environmental engineering and director of the Center for Watershed Sciences at UC Davis. 

Further Reading

Schonher, T. and S. E. Nicholson (1989), “The Relationship between California Rainfall and ENSO Events,” Journal of Climate, Vol. 2, Nov. pp. 1258-1269.

Lund, J. and J. Mount (2014), Will California’s drought extend into 2015?, CaliforniaWaterBlog.com, June 15, 2014

California Weather Blog, http://www.weatherwest.com/

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Drought a ghost of Christmas past — and present

Alan Marciochi

A California Christmas greeting card from 1977, a year of severe drought. Drawing by Alan Marciochi, courtesy of Peter Moyle

By Peter Moyle

I love this cartoon because it says so much about water and droughts in California. Alan Marciochi drew this during the 1976-77 drought. He knew what he was drawing.

A farm boy from Los Banos with a degree in biology, Alan worked for me studying endangered Modoc suckers in remote northeastern corner of California. His main stipulation in working for me was that he had to have the melon harvest season free. He could make more money packing melons in a month or two than he could make working for me in a year. I could not give Christmas bonuses.

Photo: U.S. Fish & Wildlife Service

Modoc suckers dwell in pools of headwater streams flowing through meadows and dry forests, primarily in Modoc County. Photo: U.S. Fish & Wildlife Service

For his field job with me, Alan moved to Modoc County where he soon joined a local band as a banjo player. He gained enough local trust that ranchers allowed us on their land to look for an endangered species, the Modoc sucker. I am happy to report that, partly as a result of that early work, the species has become much more abundant and there are proposals to remove it from its fully protected status.

Drought was just one of many threats to the Modoc sucker at the time. Cattle trampled its habitat during low-flow periods. Irrigators channelized and diverted key streams. Alien brown trout and green sunfish devoured the suckers, especially when they were concentrated in a few pools. Restoration projects have greatly improved conditions for the sucker, but it remains vulnerable to severe drought.

In Alan’s cartoon, the line queuing up to the weary Santa could easily be made up of 120 species of California native fishes, each asking for more water. In this unexpectedly wet holiday season, Santa may be able to appear less weary, but there is still not enough water to go around for all fish and human uses — even in wet years.

The Modoc sucker story suggests we can work things out in ways to sustain our native fishes in a human-dominated landscape, such as on ranches. I like to keep this message of reconciliation in mind, especially during the holiday season. A few large gifts of water to the fish would be nice, however.

Peter Moyle is a distinguished professor of fish biology and associate director of the Center for Watershed Sciences at UC Davis.

Further reading

Moyle, P. B. and A. Marciochi. 1975. Biology of the Modoc sucker, Catostomus microps, in northeastern California. Copeia 1975:556-560

Moyle, P. B. 2002. Inland Fishes of California. Revised and expanded. Berkeley: University of California Press. 502 pp

 

 

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