How engineers see the water glass in California

Engineering a water glass at 50 percent. Source: xkcd.com

Engineering a water glass at 50 percent. Source: xkcd.com

How do engineers see the water glass in California? Mostly the same as they did four years ago when this blog was first posted, though with today’s drought the glass is perhaps down to a quarter full — or three-quarters empty. 

By Jay R. Lund

Depending on your outlook, the proverbial glass of water is either half full or half empty. Not so for engineers in California.

Civil engineer: The glass is too big.

Flood control engineer: The glass should be 50 percent bigger.

Army Corps levee engineer: The glass should be 50 percent thicker.

Mexicali Valley water engineer: Your leaky glass is my water supply.

Delta levee engineer: Why is water rising on the outside of my glass?

Dutch levee engineer: The water should be kept in a pitcher.

Southern California water engineer: Can we get another pitcher?

Northern California water engineer: Who took half my water?

Consulting engineer: How much water would you like?

Environmental engineer: I wouldn’t drink that.

Water reuse engineer: Someone else drank from this glass.

Groundwater engineer: Can I get a longer straw?

Academic engineer: I don’t have a glass or any water, but I’ll tell you what to do with yours.

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

Further reading

Munroe, Randall. Glass Half Empty. xkcd.com

Posted in Uncategorized | Tagged , | 5 Comments

The Coming Droughts of California in 2017 – November 27, 2016

By Jay Lund

California is a big diverse place.

California probably will experience droughts this year of different types in different places, and no drought at all in some places, simultaneously.  Even if conditions this year are very wet, with flooding, parts of California will have drought issues. (This is what makes California a great place to work on water problems.)

The first two months of this new water year have been wetter than average in the north and much drier than average in the south.  But it is still early days.

Reservoir and Groundwater Storage Conditions

Reservoir storage in California is now about 2.5 million acre-feet below historical averages for this time of year.  (This is 0.8 maf better than 2 months ago.)  Some major reservoirs are below average, particularly Oroville, Trinity, San Luis, New Melones, and the Tulare Basin reservoirs.  Cachuma Reservoir near Santa Barbara is in the worst shape at 7% of capacity or 10% of average storage for this time of year.

Groundwater will be recovering in northern parts of California, with less recovery in large parts of the southern Central Valley.  (Can anyone suggest a set of online well elevation records in different parts of the Central Valley to create a groundwater storage index?)

October was a nice wet month, so soil moisture in much of the Sierras and Central California is improving, but remains in drought conditions (worsened by unusually high temperatures).  Conditions for forests and native fishes remain depressed and will see drought impacts for years after hydrologic conditions improve.

This seemingly bad situation is substantially better than in this time a year ago.  Something to be thankful for.

nov-res-cond-2016b

Major reservoir storage in California, 26 November 2016

Precipitation Conditions

North of the Delta, so far we have above average precipitation and improving storage in most Sacramento Valley reservoirs.  In the San Joaquin Valley, this water year’s precipitation is about average so far.  But further south, the Tulare Basin has less than 50% of average precipitation so far this water year.  And temperatures remain higher than average.  So far, no snowpack – it is still a bit early.

Thoughts for the coming drought year

So far, overall drought conditions are mostly improving, but unevenly.  We won’t really know how wet this year will be until late March.  In October, this blog looked at overall drought conditions from several perspectives and statistical projections for the new water year.  (This month’s election reminded us of the reliability and unreliability of statistical projections.)

Even if this year is wet, parts of California will experience drought or residual effects from five years of drought.  The California Drought of 2017 will likely take several forms:

  1. Dry residential and community wells drought, affecting rural areas with lowered groundwater tables. Many of these household wells and small systems are in a precarious state even in wet years.
  2. Drought of surface irrigation water. Here surface water is unavailable and farmers mostly increase groundwater pumping, often at a higher cost and increasing regional groundwater depletion. This drought is more likely south of the Delta.  Less surface being less available than irrigation demands south of the Delta is now a normal condition, due to a host of hydrologic, infrastructure, groundwater sustainability, economic and environmental factors, worsened by drought.
  3. Higher groundwater pumping cost drought. Even if this year is wet, many areas that pump groundwater will still face higher pumping costs for some years or longer from the drought’s cumulative groundwater depletions.
  4. Forest drought (including snow drought). Here, lack of soil moisture or its more rapid depletion with higher temperatures affects forest ecosystems.
  5. Ecosystem drought. Problems for some fish are likely to continue even if the year is wet, due to drought-depletion of some native fish populations.  Dry conditions could also affect waterfowl. A drought of cold water in some reservoirs might affect both fish and farmers disrupted by reoperation of reservoirs.
  6. Urban drought. So far, most urban areas have pretty healthy water supplies.  The big exception is Lake Cachuma in the Santa Barbara area, now at 10% of its long-term storage for this time of year.
  7. We could easily see some drought surprises. The wet season is still young. Welcome to California water, where anything can happen.

It is best to prepare for another drought year (and prepare for floods as well).

Here are some web sites to watch, mostly from the California Department of Water Resources’ fine California Data Exchange Center (CDEC) at http://cdec.water.ca.gov.

Reservoir levels:

Snowpack (none yet):

Precipitation:

Weather:

Jay Lund is Director of the UC Davis Center for Watershed Sciences and Professor of Civil and Environmental Engineering at UC Davis. 

A neat reading

Posted in California Water, Drought | Tagged | 5 Comments

Human Use of Restored and Naturalized Delta Landscapes

By Brett Milligan, Assistant Professor, UC Davis Landscape Architecture and Sustainable Environmental Design and Alejo Kraus-Polk, PhD Geography candidate, UC Davis

white-slough

Ponds #9-13 of White Slough Wildlife Area. Ponds are borrow pits from building I-5 while beginning a Delta peripheral canal. When the peripheral canal was voted down in 1982, these lands were retained by California’s Department of Fish and Wildlife for “interim” management, today as part of the White Slough Wildlife Area for fishing, hunting, wildlife viewing and other recreational activities. Photo by Brett Milligan.

delta-restoration-map

Restored Landscapes in the California Delta: Current and planned EcoRestore projects and other restoration projects completed, in progress or in planning. Data from the California Department of Water Resources and EcoAtlas. Map by Brett Milligan and Prashant Hedao.

Current legislation and plans for the California Delta call for restoring tens of thousands of acres of aquatic and terrestrial habitat, which will require large changes in land uses and cultural patterns.  In addition to planned ‘restoration’, unplanned ‘naturalization’ also occurs in the Delta, from the flooding of islands or the abandonment of previously managed land.  These newly feral or semi-wild landscapes will remain subject to human use and give rise to new scientific, economic, and recreational uses.

We recently completed a study of how restored and naturalized landscapes are being used by people, the effects of those uses, and how those uses might be better planned.  We surveyed or interviewed more than 100 land managers, scientists, landowners, law enforcement personnel, agency representatives and Delta residents and reviewed existing Delta planning literature, field work and case studies. In general, our research supports advancement of an ecosystem reconciliation approach, which seeks synergies between ecosystem needs and the desires of those who live, work and play in the Delta, now and in the future.

We found that:

Restored and naturalized landscapes are strongly affected by human use, presence and management.  These landscapes reflect their former domesticated states and uses, which were mostly agricultural. This newly feral quality, along with accelerated rates of climate change, ensure that these ‘restored’ landscapes will be novel and unprecedented ecologically.  These landscapes are human places as much as they are ecosystems and have a long history of use for subsistence, recreation, illicit and unregulated activity, and more recently, for science.  Combined with the extensive urbanization surrounding the Delta, human uses of these landscapes will remain diverse and pervasive.

Restored and naturalized landscapes are often subject to multiple and conflicting uses and values.  Experiences and cultural practices are typically marginalized in restoration planning, but have understudied effects on these landscapes. Politics, laws, accessibility, amenities, ways of living and territoriality all affect what these places will become.  There are different values related to the evolving Delta, beyond science and restoration goals. Diversity of values should be included in planning, design and management, as they affect the performance of restoration efforts.

liberty-island

Entrance Gate to Liberty Island. Photo by Brett Milligan.

Reconciling human uses with ecological restoration will require more comprehensive planning and design.  Plans and designs should serve multiple beneficiaries, both non-human and human.  Regional connectivity (landscape networks) also matters in terms of access and ecological functions.  Restoration planning and design should seek community involvement and stakeholder participation, critical for long term success.  Human uses should be integrated into restoration planning from the beginning, rather than as an afterthought, as these uses can increase the value and support for these projects, contribute to the local and regional economy and deter undesirable and unsanctioned uses.

Funding for recreation and human uses in restoration planning is an important long term investment, and is recommended in the Delta Plan.  Design and management choices at the beginning of a restoration project have a strong bearing on future relationships and conditions.  We should design and plan for pleasure, aesthetics and accommodate diverse user experiences, to build stronger constituencies and public appreciation.  Not accounting for public use and place values tends to lead to problems and unintended uses.  Designing for human uses at the outset of a project will cost more initially, but should reduce long term conflicts among the objectives of management, enforcement and desires of users.  Ecological restoration initiatives, such as Ecorestore, should continue to integrate and fund participatory restoration planning, such as the former Delta Dialogues and Delta Restoration Network projects and the current Delta Conservation Framework.

franks-tract

Floating Duck Blind, Franks Tract. California State Parks manages a duck hunting program on Franks Tract. Hunters apply for permits to build blinds at specific coordinates within a grid of evenly spaced locations across the lake. The blinds must be removed at the end of the hunting season. Photo by Brett Milligan.

Human uses of restored landscapes should be integrated into adaptive management.  The Delta Independent Science Board’s Adaptive Management review posits that a, “more holistic and integrated approach to science­ based adaptive management in the Delta is needed to face both current and future challenges” (DISB 2016).  Human uses can be compatible with restoration objectives through effective and creative adaptive management.  However, like the dynamic nature of the Delta’s ecology, human uses are not determinate, varying with geographic contexts and across time. Therefore, human use studies specific to the Delta’s landscapes — scientific, recreational, etc. — should be done regularly to better inform management.

The public is an overlooked asset and advocate for restoring and monitoring Delta landscapes.  The Delta’s novel ecologies and efforts to guide them should be highlighted in Delta literature, marketing and advertising.  In particular, citizen science offers a range of win-win methods to collect broader low-cost monitoring data.  It also offers science an avenue for greater public acceptance and understanding (McKinley et al. 2015).  Although citizen science is almost non-existent in the Delta it is widely and successfully practiced in the San Francisco Bay Area.  Experimentation with citizen science should be a Delta science priority.  We should also experiment with the variety of interactive, real time, and geolocative digital media available to users and visitors of the Delta. There is much potential for the creative use and application of such media for fostering awareness and stewardship of Delta restoration efforts.

stone-lakes

Native plant restoration. Native plant hedgerow maintained Stone Lakes National Wildlife Refuge by the Sacramento Tree Foundation, Winter, 2015. Hedgerow provides habitat and a buffer and natural fence to discourage trespassing onto adjacent, private farmland. Photo by Brett Milligan.

Our research suggests the need to shift how restored Delta landscapes are considered in planning, policy and design.  We advocate for including human presence integrally in these landscapes.  Doing so will make restoration efforts more realistic and effective.

Reconciling human uses with restoration objectives requires a broader view of stewardship.  Enhancing and planning for human use experiences could help reconcile multiple issues of concern.   Integrated adaptive management efforts with adequate resources should play a role in the present and future of restored and naturalized Delta landscapes.

This shift in approach is timely as restoration efforts gain momentum and expand.  A 2016 DISB report on adaptive management and the IEP Delta Science Agenda both signaled the need to integrate human factors in designing for ecological recovery in the Delta.  Yet there is a considerable void in the literature and in stakeholder conversations on the topic.  This study provides a rationale for why human dimensions of adaptive management are needed in restoration and broader management efforts, and why giving human dimensions more rigorous consideration can assist in meeting these goals.

Further reading

Human Use of Restored and Naturalized Delta Landscapes Report:
Human Use Report Executive Summary
Human Use Report for screen viewing (spreads)
Human Use Report for printing
Human Use Report Appendix

DISB. 2016. “Improving Adaptive Management in the Sacramento-San Joaquin Delta.” DISB.

McKinley, Duncan C., Abraham J. Miller-Rushing, Heidi L. Ballard, Rick Bonney, Hutch Brown, Daniel M. Evans, Rebecca A. French, et al. 2015. “Investing in Citizen Science Can Improve Natural Resource Management and Environmental Protection.” Issues in Ecology 19. pubs.er.usgs.gov. http://pubs.er.usgs.gov/publication/70159470.

Posted in Delta, Planning and Management, reconciliation, Restoration | Tagged , | 2 Comments

Allocating a Share of San Joaquin River Water to the Environment Shows Promise

Source: California Department of Water Resources

Source: California Department of Water Resources

By Jeffrey Mount, Brian Gray, Ellen Hanak, PPIC Water Policy Center, Peter Moyle, UC Davis Center for Watershed Sciences

Introduction

In September 2016, the State Water Board released its draft plan for new environmental flow requirements in the San Joaquin River watershed. The board’s proposal contains a novel—and controversial—recommendation. Instead of following the traditional approach of setting minimum flows to meet specific environmental needs at specific times of the year, the board proposes to allocate a block of water each year to improve habitat for fish and wildlife in the lower San Joaquin River and its tributaries—the Stanislaus, Tuolumne, and Merced.

As we have argued in several recent reports, assigning a block of water to the environment has numerous advantages over the traditional regulatory approach. Done well, it could improve ecosystem performance and the efficiency of environmental water use, while reducing uncertainty for other water users.

Here we outline the essence of the board’s proposal and describe its strengths and areas for improvement. We conclude with some suggestions for how these ideas could be incorporated fruitfully into settlement negotiations with stakeholders in the watershed.

The board’s proposal: Allocating a share of water for the environment

Native fishes in the Lower San Joaquin River and its tributaries—particularly salmon and steelhead—have been declining for decades. The board has authority to address this decline by setting flow requirements to protect beneficial uses of California’s waters. This authority derives from a variety of California laws that are not dependent on either the federal Clean Water Act or the Endangered Species Act.

For fish, the board traditionally sets minimum flow standards tailored to meet the requirements of specific life stages of each of the protected species (e.g., pulse flows to facilitate migration up and down the river, cold water for eggs and young fish). These flows are made available through a combination of releases from reservoirs and limitations on diversions by other water users.

The proposed new approach is to allocate a portion of the February-through-June “unimpaired flow” on the Stanislaus, Tuolumne, and Merced tributaries to native fish. Unimpaired flow is the volume of water that would be present in the tributaries without reservoirs or diversions.

The plan proposes that an average of 40% of this flow—with a range of 30-50%—be assigned to meet environmental objectives. We have no position on the merits of this proposed share, which is likely to be a matter for negotiation on each tributary.

More important is the flexible way that environmental managers could use this water. Under the proposal, they could shift flows as needed for different hydrologic conditions or locations to meet biological goals for protected species. This could include storing water for pulse flow releases—such as to improve water quality or provide migration cues for fish—and holding water until late summer to bolster cold water releases from reservoirs.

Why this approach is a good idea

The board’s proposal to allocate a flexibly managed block of water to the environment is an improvement over the traditional setting of minimum flow standards in three ways:

  • Efficiency: The block approach allows for better use of environmental water to benefit fish. Managers can more easily adapt to changing conditions such as droughts and floods, time flow releases for maximum effect, vary the way they apply water from year-to-year, and more nimbly respond to new biological and ecological information. This would increase the efficiency of environmental water use while also improving its effectiveness.
  • Predictability: A block of water is simple, transparent, and easier to incorporate into environmental and operations planning.  Assigning a specific quantity of water to environmental uses would give more certainty to other water users, because they would know the percentage of unimpaired flow available to them.
  • Shared responsibility: Allocating a flexibly managed block of water to environmental uses would ensure that the environment is better integrated into the water rights system. Environmental water managers would have a seat at the table in water management, deciding how best to use their allocation just as other water users do, and the environmental water block would share equally in abundance and shortage along with other beneficial uses.

What would make this approach even better

In addition to this novel approach to establishing flow standards, the draft plan encourages stakeholders and interested parties to negotiate settlements that they would submit to the board for approval. Such negotiations are a good way to harness local knowledge, creativity, and cooperation.

We recommend that negotiators and the board retain the idea of allocating a block of water to the environment and consider several improvements:

  • Allow carryover: The draft plan requires that all environmental water be used in the same water year. To enhance efficiency and to hedge against drought, it should be possible to store some environmental water in surface reservoirs or groundwater basins (with rules to avoid impacts to other users). A good example of the benefits of integrating groundwater and surface water storage with environmental flow management comes from the Yuba River watershed in northern California.
  • Allow trading: Environmental water efficiency also would be enhanced if the plan explicitly allowed the buying and selling of this water. A good example comes from Australia, where environmental managers regularly lease some of their water to fine-tune flow management in different catchments. Some revenues from leasing are also used to support ecosystem investments.
  • Encourage augmentation: The existence of a well-managed environmental water budget would present an opportunity for better employing conserved urban and agricultural water for environmental purposes. Allowing the budget to be easily augmented with water acquired on a permanent, long-term, or temporary basis through voluntary purchases or donations would increase resources for environmental management.
  • Assign responsibility: The proposed governance structure for environmental water management is a large, multi-party committee of regulatory and planning agencies, project operators, water users, and other stakeholders (Draft Plan, Appendix K, page 32). This structure is cumbersome and lacks the independence and flexibility needed to administer the block of water in a timely fashion. The revised plan should create an environmental water manager—perhaps similar to the environmental water holder in Victoria, Australia—with authority and staffing to administer the environmental water for defined biological objectives.
  • Improve planning: The long-range biological goals and objectives—beyond improving salmonid populations—are not well articulated in the current plan. Management of the Stanislaus, Tuolumne, and Merced tributaries needs an overarching biodiversity plan that takes a broader, ecosystem-based approach and defines how the environmental water allocation would benefit salmonids as well as other riverine, riparian, and wetland species. The plan should achieve multiple environmental benefits from the water, focusing on different priorities in different types of water years. Such a plan could be developed relatively quickly, based on available scientific information and with input from stakeholders. The biodiversity plan should be revised every 7-10 years, based on improvements in scientific understanding of ecosystem performance. Victoria, Australia provides a model for developing pragmatic, ecosystem-based plans to maximize the benefits of environmental water.
  • Monitor and Adapt: It is critical that management of the environmental water allocation be supported by a robust, transparent, and science-based monitoring program. This program should report to the environmental water manager, who would use the information to guide annual allocation and use decisions, adaptation and management experimentation, and long-term planning and evaluation.  Funding this effort may require pooling of resources among agencies and water users.

Conclusion

The board’s proposal to use a percentage of unimpaired flow as an environmental standard and budget for the Stanislaus, Tuolumne, and Merced tributaries has generated a great deal of controversy in the water-user community. While this is understandable, we encourage all interested parties to carefully examine the merits of this approach and to consider its compensating advantages. Block allocations of environmental water—flexibly managed and supported by science, sound governance, and planning—can be an effective tool for achieving the twin goals of ecosystem protection and water supply reliability.  Negotiating settlements that seek to achieve multiple benefits from blocks of environmental flows is a promising direction for using California’s water more efficiently and effectively.

Further Reading

California State Water Resources Control Board. 2016. Draft Revised Substitute Environmental Document in Support of Potential Changes to the Water Quality Control Plan for the Bay-Delta: San Joaquin River Flows and Southern Delta Water Quality.

Escriva-Bou, A., H. McCann, E. Hanak, J. Lund, and B. Gray.  2016. Accounting for California’s Water. Public Policy Institute of California.

Gray, B., E. Hanak, R. Frank, R. Howitt, J. Lund, L. Szeptycki, and B. Thompson.   2015. Allocating California’s Water: Directions for Reform. Public Policy Institute of California.

Lund, J., E. Hanak, B. Thompson, B. Gray, J. Mount, K. Jessoe. 2014. Why give away fish flows for free during drought? California Waterblog.

Lund, J. 2015. Urban water conservation for birds.  California Waterblog.

Mount, J., B. Gray, C. Chappelle, J. Doolan, T. Grantham and N. Seavy. 2016. Managing Water for the Environment During Drought: Lessons from Victoria, Australia. Public Policy Institute of California.

Posted in California Water, Uncategorized | Tagged , , , | 7 Comments

The North Delta Habitat Arc: an Ecosystem Strategy for Saving Fish

Cache Slough sunrise, April 2013. Photo by P.B. Moyle

Cache Slough sunrise, April 2013. Photo by P.B. Moyle

Peter Moyle, John Durand, Amber Manfree.  Center for Watershed Sciences, University of California, Davis.

Delta native fishes are in desperate condition. Over 90% of fish sampled by diverse means belong to non-native species.  Native species such as delta smelt are on a trajectory to extinction.  If we are going to reverse this trend, we need to recreate a functioning estuary. This in turn requires more than a piecemeal collection of restoration projects, but an ecosystem-based plan of action, which we present here.

First, we remind you of some basic realities about the Delta:

  • The Delta is and will continue to be a central node in California water supply system, which requires moving Sacramento River water through the Delta to pumping plants.
  • Upstream diversions prevent a substantial amount of water from reaching the Delta.
  • There will be major changes to the Delta from multiple factors, including sea level rise, earthquakes, climate change, and (perhaps) methods of water export.
  • Areas of the Delta dominated by Sacramento River flows are very different ecologically from those on the San Joaquin side.
  • The Delta is an increasingly hostile place for native fishes because of the combination of large-scale habitat change, alien species, and changed hydrodynamics.
  • The Delta as a whole, but especially the south and central Delta, no longer functions well as part of an estuary, because changes in flow alter the dynamic upstream-downstream gradient of habitat characteristic of estuaries.

Regardless of ‘fixes’ proposed for the present cross-Delta water delivery system, major projects to provide habitat for declining native species are needed.  Many projects are already underway or planned. These are mostly in the north and west Delta where more opportunities are provided by availability of suitable land elevations and fresh water from the Sacramento River.

delta

The Delta, showing the North Delta Habitat Arc.

Here we propose the conceptual basis for a Grand Strategy to create an inter-connected series of habitats, mostly tidal, in this region. In some respects this strategy is already underway, but it lacks a unified conceptual, scientific, institutional, and applied approach.

This Grand Strategy creates an arc of habitats connected by the flows of the Sacramento River.  The upstream end of the arc is the Yolo Bypass, and the arc continues through the Cache-Lindsey Slough-Liberty Island region, down the Sacramento River including Twitchell and Sherman Islands, and into Suisun Marsh (See figure). The Cosumnes River-Stone Lakes area would act as a connected floodplain region.  We refer to this arc the North Delta Habitat Arc but it could perhaps be called the Reconciliation Arc, recognizing the highly altered nature of the habitats, the need for continuous management, and their significant compatibility with farming and other activities.

Here are some of current features and actions occurring in the Arc:

Yolo Bypass.  This is the place where we are learning how farmed floodplains can become major contributors to conservation of fish and wildlife. Future projects are likely to include gates on the Fremont Weir to allow annual flooding on some parts of the Bypass, especially in miniature floodplains along the Toe Drain, on the east side of the Bypass.  Re-establishing a natural connection between Putah Creek and Sacramento River through the Bypass should support re-establishment of runs of salmon and other migratory fish in the creek.  Water flowing through Bypass, even as small pulses, also has potential to be a source of food and nutrients for pelagic fishes in the Delta.

North Delta.  The Lindsey-Cache Slough-Liberty Island area is widely regarded as prime real estate for restoration projects, in part because the natural drainage patterns still exist on the landscape and because of its connections with the Sacramento River.  Examples of on-going projects include the reconnection of historic tidal sloughs to Calhoun Cut, the development of a tidal marsh ‘from scratch’ as mitigation habitat, and Liberty Island Ecological Preserve.

Sacramento River.  The Sacramento River as it flows through the Delta is THE major corridor for fish migration:  four runs of Chinook salmon, steelhead, American shad, striped bass, delta smelt, longfin smelt , splittail, green sturgeon, and white sturgeon.  Maintaining flows and water quality is important for all these species.  It is likely that complex, vegetated edge habitat is very important for juvenile fishes moving downstream and perhaps for spawning of delta and longfin smelt.   The restoration of large tracts of tidal marsh on Twitchell and Sherman Islands is likely to benefit migratory species of both fish and birds, as well as to reverse subsidence and perhaps provide ‘food’ for larval and juvenile fishes through export to main channels.  We also envision using ponds within these islands to support populations of Sacramento perch and other native species.

Suisun Marsh.  Suisun Marsh is connected to the Sacramento River by Montezuma Slough, which has large tidal gates near its upstream end.   The tidal gates regulate salinities in the Marsh, keeping conditions fresher during late summer and fall. The high potential of Suisun Marsh to support native fishes is increasingly being recognized.  New projects are being started or proposed, such as finding ways to manage duck hunting clubs for both fish and ducks, creating tidal habitat that mimics conditions in remaining ‘natural’ tidal sloughs, and making Roaring River Slough into a flow-through system, rather than just a dead-end water delivery system for duck clubs.

These areas each have their own distinctive characteristics and faunas. Collectively, the many projects should be regarded as a large-scale example of reconciliation ecology, where new habitats are created and closely managed by people to meet specific goals. The biota of these new habitats is a mixture of native and non-native species that together form novel ecosystems.

Viewing the Arc as a large inter-connected and reconciled ecosystem should help us to:

  • Manage projects to benefit a full range of life history stages for key species. For example, splittail spawn on floodplains but rear in brackish tidal marsh, so they need the entire system to support their life history.
  • Coordinate management of restoration projects with water project operations.
  • Manage the system in a changing climate: longer droughts, bigger floods, and warmer temperatures.
  • Restore tidal marshes as sources of food for pelagic fishes such as delta smelt.
  • Compare outcomes of different restoration strategies.
  • Assess how tidal marsh restoration projects affect tidal flow in projects, given that total tidal energy is more or less fixed.

We recognize that we are essentially recommending that reconciliation efforts be focused on about one third of the Delta, especially for fishes.  In the Central and South Delta, the realm of subsided, riprap-ringed islands and major pumping plants, it is hard to see much future for native fishes, although fisheries for alien fishes such as largemouth bass will continue to thrive. We will develop these concepts further in future blogs.

Further reading:

Moyle, P. B.; L. R. Brown, J.R. Durand, and J.A. Hobbs. 2016. Delta Smelt: life history and decline of a once-abundant species in the San Francisco EstuarySan Francisco Estuary and Watershed Science, 14(2). jmie_sfews_31667. Retrieved from:

Quiñones, R.M and P.B. Moyle. 2014. Climate change vulnerability of freshwater fishes in the San Francisco Bay Area. San Francisco Estuary and Watershed Science 12(3). doi:

Moyle, P.B., A. D.  Manfree, and P. L. Fiedler. 2014. Suisun Marsh: Ecological History and Possible Futures.  Berkeley: University of California Press.

Hanak, E., J. Lund, J. Durand, W. Fleenor, B. Gray, J. Medellín-Azuara, J. Mount, P. Moyle, C. Phillips, and B. Thompson. 2013. Stress Relief: Prescriptions for a Healthier Delta Ecosystem. San Francisco: Public Policy Institute of California. Available at

Moyle, P.B.  2013 Ten realities for managing the Delta.  California Water Blog. Center for Watershed Sciences, UC Davis. February 26, 2013.

Moyle. P.B. W. Bennett, J. Durand, W.Fleenor, J. Lund, J.Mount, E. Hanak, and B. Gray. 2012. Reconciling wild things with tamed species- a future for native fish species in the Delta. California Water Blog. Center for Watershed Sciences,  June 15, 2012.

Moyle, P. B., W. Bennett, J. Durand, W. Fleenor, B. Gray, E. Hanak, J. Lund, J. Mount. 2012. Where the wild things aren’t: making the Delta a better place for native species. San Francisco: Public Policy Institute of California. 53 pages.

Moyle, P.B. 2011. Reconciliation or extinction- the future of California? California Water Blog. Center for Watershed Sciences, February 8, 2011

Lund, J., E. Hanak, W. Fleenor, W. Bennett, R. Howitt, J. Mount, and P. B. Moyle.  2010. Comparing futures for the Sacramento-San Joaquin Delta. Berkeley: University of California Press. 230 pp.

Posted in Delta, Uncategorized | Tagged , , | 5 Comments

The Horror of a Salmon’s Wheel of Misfortune

By Miranda Tilcock

The Salmon Life Cycle. Illustration Courtesy of the Atlantic Salmon Trust and Robin Ade

The Salmon Life Cycle. Illustration Courtesy of the Atlantic Salmon Trust and Robin Ade

Salmon in the Stream

10 little salmon eggs, resting in a redd
1 was covered in silt, now the egg is dead
9 little alevin, with their yolks attached,
1 was washed away, and never made it back
8 little salmon fry, looking for something to munch
1 wandered too far, now it’s a striper’s lunch
7 little salmon parr, in need of food to eat
1 swam near the surface, into an egret’s beak
6 little salmon parr, swimming close to land
1 was trapped by falling waters, temperatures too hot to stand
5 little salmon smolts, almost at the ocean
1 smolt got lost, never to feed on grunion
4 little salmon smolts, so silvery and fine
1 got tangled up, stuck in a fisherman’s old line
3 large salmon adults, chasing some anchovy
1 salmon bit a baited hook, now it’s being served as sushi
2 large salmon adults, trying to come back home
1 couldn’t scale a ladder, all its energy was gone
1 last salmon adult, made its way at last
To dig its redd in pebbles, before its final gasp

It’s tough being a California salmon. There are many manmade and natural perils and predators, including humans, which want to eat you. Their life is like a horror movie! The story above is optimistic. The real world is far scarier, with each salmon egg having a 1 in 1,000 chance of returning to spawn. Numerous additional dangers, beyond those above, affect salmon at every life stage.

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A Salmon Fry. Photo credit: Miranda Tilcock

Salmon are particularly vulnerable during the fry/parr life stage due to their small size, an abundance of predators, and lack of food. The Nigiri Project study, jointly run California Trout, UC Davis, and the California Department of Water Resources, is quantifying the effects of floodplain habitat on salmon growth, to increase the likelihood that salmon will survive past the vulnerable fry/parr life stage. Slowing and spreading water across the landscape leads to far more productive food webs and provides salmon additional time to grow, compared with channelized rivers. Chlorophyll production increases in shallow, slow moving water and plant materials decompose in standing water, in turn fueling food webs. Chlorophyll and bacteria are key foods for zooplankton communities; their abundance allows zooplankton to reproduce at astronomical rates.

In 2016, the Nigiri Project compared food web communities in the Sacramento River, Tule Canal, and nearby managed floodplains. The three pictured samples were taken on March 25, 13 days after natural floodplain inundation. It’s pretty clear where the food is! Reconnecting floodplains to rivers provides salmon access to water rich with food resources and lacking in predators. As such, young salmon benefit by gain fat quickly, allowing them to essentially “pack their lunch” for the long voyage to sea. Like bears in winter, salmon live off these fats when food is scarce during outmigration or in the ocean.

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Which has more salmon food? Three zooplankton samples taken March 25, 2016 just 13 days after a natural flood. Photo credit: Miranda Tilcock

The Center for Watershed Sciences is active in research and various educational outreach programs. Schools visiting Knaggs ranch use visual aids, like the Wheel of Misfortune, to demonstrate how difficult life is for salmon. The wheel, originally developed by the Department of Fish and Wildlife, is numbered from 1-24. Each number corresponds to a deadly fate on the matching Board of Misfortune, designed and built by Mollie Ogaz and Miranda Tilcock from the UC Davis Center of Watershed Sciences.

wheelofmisfortune

The Salmon Wheel of Misfortune.

Each color on the wheel represents a different salmon life stage. The wheel is proportioned to show how vulnerable salmon are at each life stage. For example, most of the wheel is bright yellow indicating the fry stage, a periods when salmon are most vulnerable to predation and other perils due to their small size and lack of food. Some examples of salmon mortality include eggs being washed away in a flood, fry being eaten by other fish, birds, or humans, smolts getting lost in the Delta, and adults being caught by anglers. The best salmon fort

wheel5

A student is reading their salmon fortune after spinning the wheel. Photo credit: Megan Nguyen.

une is the one “spawner” spot on the wheel (and in real life). After Chinook salmon spawn, they die. (There is no easy retirement.) This seems unfortunate, but for a salmon, this completes their life cycle. People of all ages enjoy spinning the wheel and seeing their fate on the board, while learning about Chinook salmon and conservation.

This iconic species is important to California’s economy and environment. The commercial and recreational fishing industries provide many jobs and revenues to the state. Salmon runs are also integral in bringing marine nutrients into less productive rivers, providing food for bears, birds, other fish, and the broader ecosystem. Salmon are also important to the human diet, being a healthy alternative to other meats. When people think of salmon conservation, dam removal and access to spawning grounds usually come to mind, but salmon require help at every life stage. Improving salmon growth and life history diversity through the restoration of historical habitat will aid in recovery.

Miranda Tilcock, a graduate from UC Davis, is a fish biologist with the Center for Watershed Sciences. Her work focuses on salmonid restoration, food web interactions, and educational outreach to local schools.

Further Reading

Grosholz, E., and E. Gallo. 2006. The influence of flood cycle and fish predation on invertebrate production on a restored California floodplain. Hydrobiologia 568:91-109.

Schemel, L. E., T. R. Sommer, A. B. Müller-Solger, and W. C. Harrell. 2004. Hydrologic variability, water chemistry, and phytoplankton biomass in a large floodplain of the Sacramento River, CA, USA. Hydrobiologia 513:129-139.

Center, USGS Western Fisheries Research. “Questions and Answers About Salmon.” USGS Western Fisheries Research Center. USGS, 13 Jan. 2013. Web. 27 Oct. 2016

Innovations in floodplain modeling: A test drive on the Yolo Bypass.” California Water Blog. October 18, 2013

Reconciling fish and fowl with flood and farming” California Water Blog. December 2,  2014.

Salmon experiment gets new twist in Yolo Bypass.” Sacramento Bee. February 19, 2016

Get Involved

Seafood Watch

Putah Creek Council

Gifts to Watershed

Nigiri Project

 

Posted in Conservation, education, Fish, Floodplains, Salmon, Uncategorized | Tagged , | 3 Comments

Evaluating California’s Adjudicated Groundwater Basins in the SGMA Era

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A groundwater well. Photo taken by DWR.

By Ruth Langridge, University of California – Santa Cruz [i]

Groundwater is a critical resource in California. While the 2014 Sustainable Groundwater Management Act (SGMA) established new requirements and increased state oversight for many overdrafted basins,[ii] groundwater basins adjudicated before the passage of SGMA are exempt from the statute’s requirements[iii].

Groundwater adjudication is where water users turn to the courts to resolve a dispute about water in a basin[iv]. Theoretically, the court defines and quantifies water rights for all groundwater users in the basin, and appoints a Watermaster to ensure that the basin is managed in accordance with the court’s adjudication decree. Prior to adjudication, a “physical solution,” often involving allocating a “safe yield” quantity among users and importing water, may be negotiated, and the court can accept it in whole or in part, or reject it and craft a different solution to manage the basin.

Adjudicated basins underlie major areas in the state, including much of the Los Angeles and Inland Empire region along with desert and coastal areas[v]. Most are in Southern California, with little precipitation and heavy dependence on imported water.  Many basins were adjudicated to reduce overdraft and support additional growth through the importation of water, and consequently establish responsibility for paying for the imported water.

While adjudication is often promoted as the most efficient institutional approach to manage groundwater in the state[vi] there was limited analysis of the recent condition of adjudicated basins. The State Water Resources Control Board contracted with our research team to evaluate how adjudicated basin performance aligned with SGMA’s goals for sustainable groundwater management[vii]. We reviewed judgments, technical literature and other archival sources and conducted telephone interviews with key managers and participants in the adjudication process. The Watermaster, a technical expert, or a lawyer who participated in the adjudication process, reviewed and commented on each basin summary. Some conclusions from this examination are summarized below.

Groundwater adjudication is fundamentally not about the sustainable management of a groundwater basin.

Rather, adjudication is about the court resolving a controversy between parties about a problem in the basin and designating who is responsible for providing a solution. Controversies can include whether the basin is in overdraft, who has a right to water, how much water can be withdrawn individually and collectively, who is responsible for providing or paying for sufficient water for future growth, and how overdraft and safe yield should be defined and calculated. Adjudication is rarely about the full spectrum of requirements for sustainable management addressed in the SGMA. This is a central issue with adjudications if the goal is the sustainable management of a groundwater basin. Moreover, although the court in principle resolves the initial questions posed in adjudication, parties frequently return to court.

Water rights are the central focus of adjudication

The legislature noted this narrow reach of adjudication in its definition of “comprehensive adjudication” as “an action filed in superior court to comprehensively determine rights to extract groundwater in a basin.”[viii] The court may approve a physical solution to remedy the problem in the basin, and the physical solution can overlap with some goals of the SGMA. However, the sustainable management of a groundwater basin is not the underlying purpose of the adjudication or the role of the court.

In practice, individual water rights often are not quantified in adjudications. Although California’s water laws usually dictate the priority of water rights, other factors, including the needs of the individual parties, are often negotiated and incorporated into final judgments. We found that allowable withdrawals often became concentrated in a small number of users in the years after adjudication. Small groundwater users and disadvantaged communities are rarely included in the physical solution.

Established water rights are difficult to alter, but the conditions placed on water rights in a basin can be quite flexible and vary considerably. Requirements to reduce demand, to pay for replenishment water if a water right is exceeded, carryover credits, and whether a water right can be transferred vary by basin. Each condition can affect both the sustainable management of the basin and the communities that rely on the basin for water supply.

With the exception of basins under mutual prescription, requirements to reduce demand did not necessarily apply equally to all pumpers. Aligning with California water rights priorities, overlyers were often allowed to pump with  limited restrictions, generally did not have to reduce pumping until appropriators reduced their withdrawals, and sometimes did not have to reduce pumping at all, or only in an extreme drought. With respect to carry-over credits, no expiration date resulted in a large accumulation of stored water credits in some basins that if used could result in significant basin overdraft.

Transfers are widely promoted to facilitate the market-based exchange of water rights. Most transfers in adjudicated basins are from overlyers, usually agricultural users, to appropriators, who are municipalities or water purveyors. Transfers affected land use and had both positive and negative changes. In the Mojave Basin adjudication, a desert area with little precipitation, some farmers sold their production rights, usually to municipal producers. This generally occurred in the Alto Subarea, and the transfers supported significant municipal growth[ix].  It is difficult to temporarily “fallow” a large municipal area during an extreme drought.

Approaches to determining safe yield,[x] overdraft, and groundwater trends are variable with no standards to determine these quantities.

The court is theoretically tasked with calculating the “safe yield” of a basin in determining water rights[xi]. SGMA defines sustainable yield as “The maximum quantity of water, calculated over a base period representative of long-term conditions in the basin and including any temporary surplus, that can be withdrawn annually from a groundwater supply without causing an undesirable result.” Undesirable results include permanently lowered groundwater levels, subsidence, degradation of water quality in the aquifer, or decreased stream flows[xii]. These terms are defined in multiple ways among adjudicated basins and in some basins are not calculated or used[xiii]. Additionally, specific metrics in many basin are often calculated relative to a previous base period of pumping[xiv] and frequently do not account for future climate change impacts.

Overdraft definitions also varied and most basins do not address accumulated overdraft. Additionally, controlled overdraft, sometimes called temporary surplus, is a strategy in several basins. This is where the amount is withdrawn exceeds the safe yield of the basin to create storage space to capture water in wet years. An issue is whether water will be available to the basin in wet years and if it will be used to recharge groundwater.

Most adjudicated basins rely on imported water to manage overdraft and/or to provide for future water needs. With climate change, more emphasis on net water use reduction is essential.

The heavy reliance on imported water is currently problematic for many basins as the cost of imported water has increased and it has become less available, and some basins anticipate that cost and scarcity will continue to be problems in the future.

A positive feature of adjudication is that a management structure is usually put in place.

The Watermaster is supposed to monitor the basin and provide annual reports to the court, which has continuing jurisdiction. Watermasters in many basins did provide strong oversight, but the appointment of a Watermaster did not always occur or did not occur in a timely manner, and reporting was not always required or was limited in scope.

The key challenge will be to resolve conflicts between strategies to move towards sustainable groundwater management and the priorities of individual water rights holders.

We recommend that adjudications always include a groundwater management plan, and annual reports that are accessible with a clear standardized format and conclusions. Projections for future climate changes and demographic shifts should be incorporated into water supplies and demands, and definitions of safe yield should incorporate consideration of interconnections between surface and groundwater and pumping impacts on relevant ecosystems.

To bring adjudication outcomes into line with SGMA, in 2015 the Legislature enacted two bills that primarily focus on reducing the costs and extended time period of the adjudication process[xv]. They also create processes to help ensure that adjudication is fair, comprehensive and aligned with SGMA goals for sustainable groundwater management. While the legislation does not force an adjudication to comply with the substantive terms of SGMA, the court needs to first consider any existing SGMA plan when adopting a physical solution[xvi].

The literature emphasizes that enforceable rules regarding access and use of common pool resources are essential for ensuring sustainable management.  Our research points to the challenges and opportunities for adjudication in attempting to reach sustainable management.

The Reports:

Ruth Langridge, Abigail Brown, Kirsten Rudestam and Esther Conrad, 2016, An Evaluation of California’s Adjudicated Groundwater Basins, Report for the State Water Resources Control Board, http://www.waterboards.ca.gov/water_issues/programs/gmp/resources.shtml

Ruth Langridge, Stephen Sepaniak and Esther Conrad, 2016, An Evaluation of California’s Special Act Groundwater Districts, Report for the State Water Resources Control Board, http://www.waterboards.ca.gov/water_issues/programs/gmp/resources.shtml

Other Relevant Work of Interest:

Enion, Rhead, (2013) “Allocating Under Water: Reforming California’s Groundwater Adjudications,” Emmitt Center on climate Change and the Environment, UCLA School of Law, Policy Brief #4;

Blomquist, William (1992) Dividing the Waters: Governing Groundwater in Southern California. ICS Press, San Francisco, CA;

Lipson, Walter (1978) Efficient Water Use in California: The Evolution of Groundwater Management in Southern California, Rand Corp: Santa Monica, http://www.rand.org/pubs/reports/2009/R2387.2.pdf

Relevant legislation

Links to the relevant legislation can be found at:http://www.water.ca.gov/groundwater/groundwater_management/legislation.cfm; 2014 Sustainable Groundwater Management Act: AB 1739 (Dickinson), SB 1168 (Pavley), and SB 1319 (Pavley). Additional bills signed by the Governor in 2015 to amend the California Water Code: SB 226 (Pavley) – addressing groundwater adjudications, SB 13 (Pavley), AB 939 (Salas), and AB 617 (Perea)

[i] This work was supported by UC Water Security and Sustainability Research Initiative funded by the University of California Office of the President (UCOP) (Grant No. 13941). Learn more at http://ucwater.org.

[ii] SGMA covered 127 high or medium priority basins that were designated as high or medium priority under the California Statewide Groundwater Elevation Monitoring (CASGEM)

[iii] The SGMA was followed by the passage of Assembly Bill 1390 (AB 1390) and Senate Bill 226 (SB 226) in 2015 that provide some procedures for groundwater adjudications.

[iv] Adjudication can be a civil action filed in a county superior court or it can be a process initiated by the State Water Resources Control Board, although the latter is rare.

[v] The West Coast and Central Basins alone are two of the most utilized urban basins in California with a service area that is home to over ten percent of California’s population residing in 43 cities in southern Los Angeles County (http://www.prnewswire.com/news-releases/wrd-board-approves-landmark-master-plan-to-expand-groundwater-supplies-300341313.html).

[vi] While problems include the cost and the extended period of litigation, the benefits are considered to be the assignment of property rights with a transferable water entitlement, and the ability of the Watermaster to regulate groundwater production while also allowing water users flexibility in water planning. See Enion, Rhead, (2013) “Allocating Under Water: Reforming California’s Groundwater Adjudications,” Emmitt Center on climate Change and the Environment, UCLA School of Law, Policy Brief #4; Blomquist, William (1992) DIVIDING THE WATERS: GOVERNING GROUNDWATER IN SOUTHERN CALIFORNIA. ICS Press, San Francisco, CA; and Lipson, Walter (1978) Efficient Water Use in California: The Evolution of Groundwater Management in Southern California, Rand Corp: Santa Monica, http://www.rand.org/pubs/reports/2009/R2387.2.pdf

[vii] The SWRCB provided the list of all the basins adjudicated prior to the passage of SGMA. Basins with pending adjudications were not included.

[viii] Senate Bill 226 and Assembly Bill 1390 passed by the California Legislature in the 2015–2016 Regular Session.

[ix] Comment from David Seielstad, Senior Watermaster Technician, Mojave Water Agency, 8/2-15.

[x] While the term “sustainable yield” is invariably implied in court decisions, most groundwater adjudications utilize the term “safe yield.”

[xi] A distinction is made between safe yield as a purely physical metric defined by hydrologists and “sustainable yield,” which accounts for both physical and social conditions in determining appropriate withdrawals to minimize declining levels and ensure the long-term resilience of groundwater systems.

[xii] http://www.water.ca.gov/groundwater/sgm/definitions.cfm

[xiii] Safe yield sometimes refers just to local precipitation, but can also include artificial water such as imported water or recycled water, as well as return from imported flows.

[xiv] This is the case even with basins that did not use the Doctrine of Mutual Prescription (initially defined by the court in the Raymond Basin adjudication) to determine both water rights and water allocations.

[xv] SB 226 (Pavley) and AB 1390 (Alejo)

[xvi] Code of Civ. P., § 849

Posted in Groundwater | Tagged | 1 Comment

Water is for fighting over? – a review of John Fleck’s recent book

waterisforfightingforBy Jay Lund

Most expressions on Western water issues are reflex or studied advocacy favoring a single viewpoint or opposing other viewpoints.  A minority provide thoughtful and reasonably balanced insights.  John Fleck’s new book, “Water is for fighting over” is at the 1% extreme of thoughtful readable pieces on western water.  The book is one of the most insightful and helpful works on Western water since Cadillac Desert.

Although the work focuses on the Colorado River, its lessons and observations are likely to resonate throughout the American West, dry parts of the world, and for those managing natural resources more generally.  His observations represent a new and more useful view of how to manage the wicked problems of western water.

The main lessons I gleaned from the book are:

  • Water problems will not lead to the broad collapse of civilization in the American West. The West’s overall economy is now largely uncoupled from needing abundant quantities of water.  The urban economies that produce more than 90% of Western wealth have found that they can continue to grow with relatively little water use.  Conservation happens, despite its costs.
  • Only the West’s agricultural sector, which uses 70-80% of developed water supplies for a few percent of the region’s economy, is water-intensive. Fortunately, the most valuable agricultural production is about half of agricultural water use.  Even agriculture has flexibility.
  • Water is better managed when local, state, and federal interests cooperate that if they feud. The costs to all from non-cooperation should weigh heavily on advocates and stakeholders.
  • Cooperation is not easy, and is based fundamentally on individual relationships and institutional settings. Despite the existence of hundreds and sometimes thousands of local, state, federal water agencies, no one is fully in charge of Western water systems.
  • Regional, state, and federal agencies often need to carefully foster a broad network of individual relationships and establish incentives for local agencies and interests to cooperate. Without such external help (often resented in public), it is difficult for local interests to break free of the chicken games common among local water interests for their own long-term good.  (Alas, risk-averse state and federal agencies often fail to undertake these network-fostering roles thoughtfully or proactively.)
  • Shared scientific and technical understanding, developed and disseminated by these broad informal networks, is needed to support agreements. (Here again, one struggles to see state, federal, and local agencies crafting such common understanding.)
  • Some fundamental dilemmas remain for western water management. How can difficult discussions of changes in water management among often conflicting interests be small enough to make progress, since they rely on a network of informal discussions, but inclusive enough to not leave out important interests? How can less organized environmental and impoverished interests be represented?
  • Progress is often incremental, incomplete, and opportunistic. Droughts, earthquakes, and lawsuits are both problems and opportunities to make progress.  Persistence across generations is probably needed, as progress on some problems allows work on imperfections.

One quibble.  Mr. Fleck is fond of saying that the saying “Water flows uphill towards money” is a myth.  Perhaps this is true in the strictest sense that “Water does not necessarily flow uphill towards the most money”, but it is also clear that “Water does not flow uphill without money.”  Almost all Western water management is based on economic motivations, even if imperfectly in terms of economic theory.

Much like Cadillac Desert, “Water is for fighting over” is a readable and compelling overview of Western water problems, but with a refreshingly new and more positive perspective.  The book’s lack of a chapter on the sex life of a major public figure will diminish its relative readership, but I hope this oversight will not reduce the book’s public policy impact.

Real progress is possible in Western water.  Although there will be pain, we are not doomed. Progress and sustained success can come from persistent informal dedication from individuals and organizations who do not hide behind easy rhetorical myths and work towards their long term interests.  Only fighting over water is a losing battle.

Further reading

John Fleck (2016), Water is for Fighting Over: and Other Myths about Water in the West, Island Press, Washington, DC, 264 pp.  Amazon

Webinar on John Fleck’s book.

John Fleck’s blog: http://www.inkstain.net/fleck/

Jay Lund is Director of the UC Davis Center for Watershed Sciences and a Professor of Civil and Environmental EngineeringHe did a little summer reading.

Posted in education, Uncategorized | Tagged , | 6 Comments

Comparing Delta Consumptive Use: Preliminary Results from a Blind Model Comparison

By Josué Medellín-Azuara, Kyaw Tha Paw U, Yufang Jin, Quinn Hart, Eric Kent, Jenae’ Clay, Andy Wong, Andrew Bell, Martha Anderson, Daniel Howes, Forrest Melton, Tariq Kadir, Morteza Orang, Michelle M. Leinfelder-Miles, J. Andres Morande, William Li, and Jay R. Lund

As California works to improve its official accounting of water for a range of purposes, one major area lacking widely accepted quantification is the consumptive use of water for agriculture, particularly evapotranspiration (ET) from crops.  In the Sacramento-San Joaquin Delta, such estimates are important, along with other hydrologic flows, for a variety of water rights, operational, and regulatory purposes.

Consumptive use is the proportion of water removed that cannot be reused elsewhere in a basin. For crops in the Sacramento-San Joaquin Delta, this is mostly evapotranspiration. In a region’s water balance, consumptive use can become a keystone for estimating groundwater recharge, outflows from a basin, and the availability of water for water exchanges or market transactions. In places like the Sacramento-San Joaquin Delta (the Delta), crop consumptive use estimation may have the additional challenges of adjusting for a collection of localized factors such as fog, canal seepage, evaporation from canals, and widely varying wind conditions.

landuse

Figure 1. 2015 Land use in the Sacramento-San Joaquin Delta, by LandIQ.

Models for calculating consumptive use have been researched for many years and have the potential for improved accuracy in estimating Delta outflows and informing water management and diversion in this complex and fragile estuarine system.  Yet, given the many agencies, stakeholders, and institutions relying on this water system hub, self-reporting of water diversions and estimates of consumptive use are often a challenge.

In an effort to reduce the information gap and converge efforts on consumptive use research, estimation and measurement, the State Water Resources Control Board’s Office of the Delta Watermaster convened funding from several state, regional, and local Delta water agencies to do a comparative study on consumptive use for the Delta. Researchers from the Center for Watershed Sciences and the Department of Land, Air and Water Resources at UC Davis partnered with researchers from UC Cooperative Extension, DWR, NASA-Ames Research Center, USDA-Agricultural Research Service, and CalPoly’s Irrigation Training and Research Center to conduct this study. The two-season study covers the 2014-2015 and 2015-2016 water years and includes completion of land use surveys for each year, deployment of field measurement equipment (thanks to the cooperation of farmers and organizations within the Delta), and estimation of consumptive use using seven methods and models such as CalSIMETAW, DETAW, METRIC, Priestley-Taylor and SIMS.

The study includes an initial report on measurement of evapotranspiration in bare soil, and a blind comparison of evapotranspiration estimates using seven different methods, applied independently. The interim report is posted on the project website at: https://watershed.ucdavis.edu/project/delta-et

Preliminary findings show that bare soil evapotranspiration at the end of the irrigation season was close to zero in four locations selected for field measurements during September-October of 2015 (Figure 2).

dailyeta

Figure 2. Daily actual ET (ETa) measured from bare soil stations (surface renewal and eddy covariance) along with daily reference ET (ETo) from the nearby CIMIS stations. Lines are mean values across stations and gray shading represents one standard deviation from the mean.

A more extensive field campaign during 2016 includes more than a dozen measurement stations over corn, pasture and alfalfa fields, and covers more of the growing season. This will greatly improve measurement and enhance future comparisons of ET estimation methods.

Preliminary findings are that the average annual crop evapotranspiration estimated by the ensemble of the models tested in the Delta Service Area is about 1,550 thousand acre feet (TAF) (Figure 3). That ensemble estimate is roughly consistent with the annual estimates used in DWR’s California Water Plan Update 2013. Crops with the highest variation in ET estimates across estimation methods under comparison are are tomatoes, vineyards and potatoes.  All estimates are within about 20% of the median estimate with the higher discrepancies during December and January, months with lower crop evapotranspiration, and September, in which some crops are being harvested.

The fact that all estimation methods do not closely agree is not surprising, and would be highly unusual in comparisons of ET estimation. However, further work should be able to increase the agreement among these estimates. In addition, it should improve understanding of why and how much different estimation methods are likely to differ, and how modeling and remote sensing estimates are likely to differ from field estimates of crop ET.

totalet

Figure 3. Total evapotranspiration estimates for selected crops in the Legal Delta and the Delta Service Area (October 2014-September 2015). Estimates are derived from monthly average estimates of daily evapotranspiration for each method. CalSIMETAW and DETAW coverage is limited to the Delta Service Area.

Discrepancies in model estimates are driven by several factors including variation in input datasets and processes, inherent methodological differences, and other varying meteorological conditions. Refined estimates produced by all of the methods during the second year of study will use common input datasets and protocols to enhance the value of comparisons.  In addition, improved algorithm calibration based on analysis of 2015 data is likely to reduce the range of variation in ET estimates across methods and improve the accuracy and credibility of all methods.

A final report on this two-year study will include final estimates of consumptive use from all methods for the 2014-2015 and 2015-2016 water years. The final report will benefit from a longer field measurement campaign and improved common protocols and input datasets. It is expected to be available during late spring 2017.

Improving estimation of consumptive use is a step toward improving the reliability and transparency of data and analysis for water management, with potential for reducing reporting and accounting expenses for farmers and the state.

Josué Medellín-Azuara, Jay R. Lund, and Andrew Bell are affiliated with the Center for Watershed Sciences, UC Davis. Kyaw Tha Paw U, Yufang Jin,  Quinn Hart, Eric Kent, Jenae’ Clay, and Andy Wong are afiilliated with Land Air and Water Resources, UC Davis. Martha Anderson is affiliated with USDA-ARS. Daniel Howes is affiliated with CalPoly Irrigation Training and Research Center. Forrest Melton is affiliated with NASA-Ames, Monterrey. Tariq Kadir and Morteza Orang are afilliated with the Department of Water Resources. Michelle M Leinfelder-Miles is affiliated with UC Cooperative Extension.

Further Reading

Medellín-Azuara, J., Paw U, K.T., Jin, Y., Hart, Q., Kent, E., Clay, J.,Wong, A., Bell, A., Anderson, M., Howes, D., Melton, F., Kadir, T., Orang, M., Leinfelder-Miles, M., and J.R. Lund. (2016). Estimation of Crop Evapotranspiration in the Sacramento San Joaquin Delta for the 2014-2015 Water Year. An Interim Report for the Office of the Delta Watermaster, State Water Resources Control Board. Center for Watershed Sciences, University of California, Davis. Last Access September 28, 2016

Medellin-Azuara, J. and Howitt, R. (2013) Comparing Consumptive Agricultural Water Use in the Sacramento-San Joaquin Delta: A Proof of Concept Using Remote Sensing, Center for Watershed Sciences University of California, Davis. Last Access September 28, 2016.

Siegfried, Lucas J.; Fleenor, William E.; & Lund, Jay R.(2014). Physically Based Modeling of Delta Island Consumptive Use: Fabian Tract and Staten Island, California. San Francisco Estuary and Watershed Science, 12(4). Jmie_sfews_20875. Last access September 28, 2016

Acknowledgements

The authors are thankful for funding and research support provided by the State Water Resources Control Board, California Department of Water Resources, the Delta Protection Commission, the Delta Stewardship Council, the North Delta Water Agency, the Central Delta Water Agency, and the South Delta Water Agency.  The authors also appreciate the assistance provided in various capacities by Nadya Alexander, J. Andrés Morandé, William Li, Cathryn Lawrence and Barbara Bellieu, who made this report possible.

Posted in California Water, Delta, Uncategorized, Water System Modeling | Tagged | 9 Comments

Drought Prospects in California for the New 2017 Water Year – October 1, 2016

By Jay Lund

Happy New Water Year 2017!

Hopefully everyone has recovered from their celebrations.

The 2016 drought year is over.  It was milder year than the four previous drought years.  The great wet hope of the “Godzilla” El Nino did not end the drought, but brought only near average precipitation.

Going into the new water year, California remains in a drought.

Here are some highlights of current conditions, with links from the California Department of Water Resources’ California Data Exchange Center (CDEC) at http://cdec.water.ca.gov.

Reservoir and Groundwater Storage Conditions

Major reservoirs in California begin this new water year about 3.3 maf lower than long-term average surface storage on September 30.  Groundwater is likely to be recovering in the northern parts of California, but is probably continuing to drop in large parts of the southern Central Valley which are still receiving less water than expected, and are subject to overdraft even in non-drought years.  Cumulative drought groundwater overdraft probably now exceeds 12 maf. (Alas, California does not maintain estimates on long-term groundwater balances, but this will come someday.)

Total water storage is probably depleted 15-20 maf from pre-drought conditions.  Soil moisture in much of the Sierras and Central California remains in drought conditions (due to both unusually high temperatures and lower precipitation).  Like groundwater, conditions of forests and native fishes are severely depressed and are likely to see substantial drought impacts for years after hydrologic conditions improve.

But this seemingly bad situation is substantially better than in October 2015.

Many reservoirs are in pretty good shape in terms of overall storage, certainly compared with October 2015.  Shasta, Oroville, New Don Pedro, and many other sizable reservoirs are entering the new water year with near-average storage levels.  Shasta levels must now be viewed more cautiously, however, because of heightened concerns for operational disruptions due to depressed populations of endangered winter run salmon.  Most surface storage depletions (current storage relative to their historical average) remain in reservoirs at New Melones (tributary to the San Joaquin River, 800 taf depletion), Trinity (in the north, 700 taf depletion), San Luis (which relies on Delta exports to fill, 450 taf depletion), and Oroville (550 taf) and Folsom (250 taf depletion), which were depleted somewhat to make up for reduced releases from Shasta due to temperature concerns.   Lake Cachuma, which serves the Santa Barbara region is also nearly exhausted with only 14 taf remaining and a drought depletion of 135 taf.

2016wateryearmajresstorage

Figure 1. Major reservoir storage in California at end of 2016 water year

Ecosystem Conditions

Fish – Native fish populations in California are largely down during the drought, with some down by frightening percentages, such as winter run salmon.  These populations effects will likely require years of effort to recover and make management of future drought years more important.

Waterfowl – Duck populations improved considerably in 2016 from 2015, which were about 25% below the long term average.

Forests – The accumulated effects of drought and warmer temperatures are likely to leave forests susceptible to diseases, pests, and further drought conditions.  There is little that water managers can do to affect drought impacts to forests, although this might be one of the drought’s biggest and most long-lasting effects.

Native ecosystems in good shape should allow more flexibility for agricultural and urban water supply operations.  Alas, this is not the case.  Ecosystem storage, so to speak, is severely depleted.

Will the 2017 Water Year Be Dry?

Statistics from about 100 years of historical records show not a lot of correlation of unimpaired runoff between years.

wateryearrunoffsacriver1921

Figure 2. Scatter plot of Water Year runoff for Sacramento River since 1921

When digested by quintiles, Table 1, only slightly more insight is gained.  Very dry years seem more likely to beget another very dry year and not a very wet year.  And both very dry and middling years have a slight, and probably not statistically significant, chance of producing another drier runoff year. Some of these effects might be residual due to the new water year beginning with drier soil moisture and groundwater conditions than average. (Note, this quintile (20%) water year classification differs from the DWR water year classification which includes a weighting of the previous year’s runoff, and so has a built in higher correlation.)

historicalprobabilities

Table 1. Probabilities of wet and dry conditions from historical data

Thoughts for the coming drought year

Welcome to California water, where anything can happen.

It is best to be prepare for another drought year (and prepare for floods as well).

Even if precipitation is average, there will still be residual storage depletion and ecosystem effects from the previous dry years.  These effects will be harder to manage if the coming year continues to be much warmer than average.  Except for some ecosystem and rural community conditions, which remain quite serious, there is no reason for panic. (Panic is often counterproductive – urgency would be appropriate.)

Many farmers in the southern Central Valley will still feel the effects of water scarcity, even if the hydrologic drought ends, as ending overdraft and greater environmental demands and restrictions for the Delta and San Joaquin River impinge on historical water delivery expectations.  They have a long-term problem worsened by the drought.  Farmers in the Sacramento Valley face some years of disruptions in the timing of water deliveries due to temperature problems for winter run salmon.

In any event, and especially if 2016-2017 is dry, there is urgency to make progress on state, federal, regional, and local water management.  Groundwater, water conservation, water markets, and the Delta remain urgent management concerns, which will interact and require a common state water accounting system sooner rather than later.

And El Nino? The great wet hope will continue, but one should probably consider the historical correlation of El Nino with northern California runoff, below, and dissipate less time with speculative predictions and invest more time on moving California forward with its difficult water problems.

elninoindex

Figure 3. El Nino index versus Sacramento Valley runoff (maf) for the last 50 years.

2016 Water Year Precipitation

Precipitation totals for the ending water year were average-ish historically, and great compared with the previous two years, but made worse due to continued high temperatures.  Below are the final cumulative plots for the 2015-2016 water year, with some comparative companionship.

sanjoaquin2016 northsierra2016 tulare2016

Here are some web sites to watch in the coming water year.

Reservoir levels:

http://cdec.water.ca.gov/cgi-progs/products/rescond.pdf

http://cdec.water.ca.gov/cgi-progs/reservoirs/RES

Snowpack:

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

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

http://cdec.water.ca.gov/cgi-progs/products/swccond.pdf

Precipitation:

http://cdec.water.ca.gov/cgi-progs/products/PLOT_ESI.pdf – Sacramento Valley

http://cdec.water.ca.gov/cgi-progs/products/PLOT_FSI.pdf – San Joaquin Valley

http://cdec.water.ca.gov/cgi-progs/products/PLOT_TSI.pdf – Tulare Basin

Jay Lund is Director of the UC Davis Center for Watershed Sciences and Professor of Civil and Environmental Engineering at UC Davis. 

Further reading

LOIS HENRY: The backstory of a water scare you never knew about, Bakersfield.com, April 13, 2016.

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