What Are The Risks of Continuing Without One?
Written by Robert Shibatani
A fundamental tenet of applied hydrology has always been baseline data. Whether newly generated or, culled from existing archives, baseline data provides the characterizing information required for any and all analyses. This makes sense since any analysis requires a starting point; a reference point, or baseline. Regardless of the whether one is studying groundwater, reservoir operations, snowmelt runoff, instream flows, water quality objectives, or flood design, any time there is the potential to change the hydrological system (or any element within it), baseline data become a requisite metric. In the regulatory arena for water resources management, such requirements are well known.
We know for example, that new water rights, transfers, hydropower licenses, or declared water shortage provisions, all require an evaluation that focuses on anticipated changes to one or more metrics (e.g., river flows, reservoir storage, water temperature, etc.). And those changes are always measured against a baseline. Without a baseline, there is no starting point. And without a starting point, there can be no means of properly assessing the potential effects of one’s actions. This is not a new idea, in fact, environmental assessment legislation has long acknowledged this principle.
Some might argue, and many do, that California already has hydrologic baselines. This is true, but therein lies the problem. It uses many different baselines and very few, if any, are derived from the same assumptions and therefore, none are consistent. But, does this even matter? Let me answer it this way; without consistency in the use of baselines, there can be no standardized future condition, and without a standardized future condition there can be no accurate (or efficient) means of ensuring that the collective incremental contribution of effects to the natural system between and from projects, agencies, or regulatory actions can be accurately documented. Without baseline consistency, each project, regulatory action, and/or undertaking by individual agencies, will identify effects that may remain wholly unaccounted for by other projects. Accordingly, mitigation and offset strategies from any one project cannot guarantee that their benefits are not undone by another project’s mitigation commitments (since each project used a differing starting point). System wide effects analysis, such as CVP/SWP evaluation, under such ad hoc procedures, only exacerbate the challenges in effectively addressing cumulative effects.
Many of today’s differing baselines are also used interchangeably, that is to say, they are derived from differing periods of record and applied forward to differing target years. In other words, even though an assessment of future conditions is necessary, historic data are still almost exclusively relied upon to define future conditions. This is typically accomplished through hindcasting. But such practice is risky since hindcasting only has relevance, if one is assured that the historic period of record reflects the same key variables, in this case, hydrologic frequency, magnitude, and intensity, to what is anticipated in the future. While this stood true for many decades, the recognition of climate change since the 1980s has altered that relationship. This was unmistakably proclaimed by P.C.D. Milly et al. almost a decade ago, in their now well-acknowledged paper, “Stationarity is Dead: Wither Water Management?”.
As of today, there is no universally accepted, or standardized future hydrologic baseline with which all federal, State, and local agencies consistently use. This regretful fact poses a significant problem for California water resources; not so much because inconsistencies convey a level of carelessness (which it does), but rather, because the lack of consistency degrades our pursuit of legitimate solutions. So many actions and initiatives depend on the ability of the collective system to quantitatively target vital objectives. Inconsistent baselines make this collective achievement virtually impossible. And this becomes especially exasperating since the solutions are so simple.
Two issues emerge; the reluctance to include climate-sensitized future data in water project analysis and, why, for those that do, a consistent baseline between them is not used?
But before we get too far into the details, let’s answer some simple questions. First, “What is a hydrologic baseline?” In its most simplistic sense, a hydrologic baseline represents the entirety of the hydrologic regime. It includes precipitation, river flows, reservoir inflow/storage, groundwater recharge, or any of the many other elements that make up the hydrologic cycle (or water balance). For example, as part of the loss portion of a water balance, are all of the man-induced actions, such as water abstractions/diversions.
Second, “Why is a hydrologic baseline important?” As noted above, the baseline sets the starting point from which all analyses associated with a current action must be assessed. Without this, it is impossible to incrementally ascertain the effect or impact of a proposed action, or identify the appropriate level of mitigation necessary to offset the anticipated adverse effects of a proposed action in order to make it environmentally/hydrologically benign.
Third, “What is the difference between a current condition baseline and a future condition baseline?” The difference between the two is simply the time frame of reference. The current condition represents today’s existing condition. This is the easiest of the baselines to define; for it is often referred to as the “look out the window” baseline. The future condition baseline, however, is much more complex. It includes assumptions on the various accretions and depletions to the system, institutional constraints, regulatory impositions, hydroclimatic variability, and operational rules; all set into the future. While each of these elements are, in and of themselves, well known, their representation in a future context requires both acumen and confidence. Most importantly, it requires a commitment to define it, as we shall see later.
In recent years, acknowledged climatic variability and shifts in hydrology continue to change the fundamental physical character of the future condition. The timing, magnitude, and frequency of hydrologic responses have, and continue to shift towards something that is very different from what we have seen in the past. Assuming one accepts climate change (and many say they do), this is where projected future hydroclimatic conditions must be used. And yet, even now, in 2016, few agencies and their projects actually use any climate adjusted future hydrologic baseline.
In fact, I would venture to guess that at present, less than 1 out of every 5 water projects in California, include a quantified climate change module in its future condition baseline. This includes projects involving new water rights, long-term transfers, water quality certifications, water quality objectives, instream flow prescriptions, flood control design, reservoir operations, infrastructure expansions, groundwater recharge, and many more. In other words, most of today’s everyday projects. This is rather unfortunate since the information necessary to quantify a climate-sensitized future hydrologic condition has been known for over a decade. In fact, this information has already been thoroughly vetted to account for such inherent requirements as spatial downscaling and bias correction.
What this means is that despite California’s heralded claims of being a global climate change leader, the vast majority of the State’s new water projects are not being planned, reviewed, approved or implemented using quantified best available climate –sensitized hydrologic data.
So why the reticence in selecting a future climate-sensitized baseline? For one and to be fair, there is no conspiracy against doing so. For the most part, this oversight merely stems from a misunderstanding or, rather, an unrecognized appreciation of what a changing hydrological baseline really means. No one did it before, so few know or want to know how to do it now.
Insofar as the lack of consistency across agencies is concerned, provinciality has always driven water utilities, whether at the local, regional, or State levels, to do things independent of others. This is unfortunate since we know that coordination can work, and work well, if the desire is there. We know, for example, that many federal water agencies, as far back as 2009, with the passage of the SECURE Water Act, were collaborating on climate change-related long-term future water supply analyses in the western States as part of the U.S. Bureau of Reclamation’s multi-faceted Basin Studies program. This included the original CCAWG and the final members; U.S. Bureau of Reclamation, U.S. Army Corps of Engineers, U.S. Environmental Protection Agency, Federal Emergency Management Agency, and National Oceanic and Atmospheric Administration.
Today, it doesn’t take much effort to see the need for a uniform, consistently applied, future hydrologic baseline in California water resources. A few contemporary examples may better illustrate what we mean.
Assume there are two projects seeking new storage monies under Prop 1 and let’s use two real life examples; the proposed Sites and Centennial dams. Both projects, in defining a future hydrologic condition will have to follow guidance provided by an administering agency, in this case, the Water Commission and its Regulations and Guidelines for Public Benefits. Now, as most know, a future condition, is defined by several elements; future hydrology, demands, various accretions/depletions, operational rules, institutional controls, regulatory constraints, and infrastructural limitations. For future hydrology alone, the choices are numerous. For example, let’s assume that both applicants adhere to DWR’s 2015 climate change modeling guidance and pick one of the 10 GCMs identified as appropriate for California. One applicant picks CanESM2 and the other applicant chooses HADGEM2-ES. Assuming identical emission scenarios, right from the start, there is a notable differential in that one has chosen a GCM that is more biased towards a “dry” future than a wet one.
Once the atmospheric precipitation module is selected, one still has to select which of the many watershed runoff models (including snowmelt) one wishes to rely on to generate the adjusted runoff. This is important since one needs reservoir inflows to “drive” the system models such as CALSIM. So, which runoff generating model does one choose among VIC, TOP, SWAT, or MIKESHE, just to name a few? Or any of the snowmelt models like SRM or SNOBAL? For consistent hydrology, these choices matter.
Operationally is where it gets really interesting. Acknowledging that both Sites and Centennial will be integrated in CVP/SWP hydrology, this joint system must be modeled. Under the future hydrologic condition time horizon (e.g., 2035), what assumptions will the Sites project team select for, as an example, Lower American River minimum flows or the flood rule curve for Folsom Reservoir? Will those assumptions be the same between projects? And what of the other 200 to 300 or so, other assumptions that must be made in order to run system planning models, like CALSIM? What is the Sites assumption for controlling Delta inflow in the year 2035? Is it the same as to what the Centennial project team is assuming? And are either consistent with what the SWRCB is proposing under its current Water Quality Control Plan Update(s)?
As of today, neither choice would be “wrong”. Ultimately, however, if both are different, at least one of them will be….and this deliberate acquiescence towards inconsistency continues to erode analytical fidelity.
One of the biggest hurdles are the operational rules for each of the proposed new surface storage projects. These are projects where the operating rules have never before been defined. Using our real life examples again, unless the Sites project team knows exactly how Centennial Dam will be operated, it will be impossible for downstream flows to be accurately simulated. And vice versa. The manner with which one assumes how a particular dam will be operated, in turn, affects how the rest of the system is simulated, since in a coordinated system, changes in one place, will affect the hydrology in another.
But the most significant challenge in defining the future hydrologic conditions is deciding whether to include other projects? Returning to our example, does the Sites analysis assume that Centennial ultimately is in place? And, if so, by what year? Conversely, does Centennial include Sites? Those decisions will significantly affect whether the claimed public benefits from either project are conservative (likely underestimated) or, likely over-stated. Extrapolated over the entire CVP/SWP, including the Delta, where many dozens of new water storage projects may be under consideration, which of those projects are included in any one project’s individual analysis? Unless they are all included or, all omitted, what you end up with is a hodge-podge of future analyses, each one promoting their own claimed benefits, but without accurately setting a consistent future baseline. And this does not even include the WaterFIX….
A salient question for this example then becomes,
“How will the Water Commission determine, looking at the analytical hydrology (as a means of assessing the validity of the claimed public benefits), which of these two projects more accurately represents the future hydrologic condition?”
The answer is critical to the entire Prop 1 selection process since funding allocation is premised on the assumption that everyone starts at the same point.
If everyone starts at a different point; in other words, uses a different future hydrologic condition, then it becomes virtually impossible for the Water Commission (or anyone else) to fairly and accurately weigh the merits of each public benefits claim…
But it does not end there. Water related actions in California are often multi-jurisdictional; meaning, many agencies are involved at some point along the project approval timeline. Most new surface water storage projects will require a host of new permits. For new surface water storage projects, it is not unreasonable to expect that new water rights, water quality certifications, streambed alteration agreements, 404 permits, and others will ultimately be needed. How do these agency protocols differ in defining what a future hydrologic condition baseline should, or should not be? And more importantly, do they each consider and define the future hydrologic conditions in the same way?
Let’s take a closer look at the SWRCB since they are arguably the most influential water regulatory agency in the State. How will they consider future condition baselines? For example, as they review new water right petitions, which future hydrologic condition will their Division of Water Rights approve in granting a new water right/license? Will it be the same future hydrologic condition that they approve for another applicant? Will each of their Divisions of Water Quality, Water Rights, and Drinking Water, all rely on the same future hydrologic condition proposed by a particular applicant or, will each Division rely on their own independent baselines? And if the latter is true, how will they document what they have adopted in the event they get challenged?
For the SWRCB, the complexities and risks become very real. The SWRCB, separately and independently from all of the Water Commission and DWR-related new water storage actions, are responsible for significant regulatory actions of their own. A good example is their multi-phase update to the Bay-Delta Water Quality Control Plan; a revised assessment of appropriate water quality control objectives for the Delta, main stem rivers, and their tributaries. This action is based, in part, on some depiction of an anticipated future hydrologic condition. We may argue whether their chosen baseline is defensible, but the fact remains, they have assumed a particular future hydrologic condition. The issue then becomes how will this assumed future hydrologic condition compare with what they have, or will soon approve, for other regulatory actions under their authority? And what if this baseline differs from what other State or federal agencies have already chosen? Like ESA future hydrologic baselines….
To illustrate how deeply this conundrum extends, let’s identify a few plausible scenarios. Let’s say an applicant submits a petition to the SWRCB for a new water right on the Feather River (or one of its tributaries). SWRCB staff review the application, go through the various analytical adjustments and public comments, and ultimately approve a new water right. What if the future hydrologic condition relied upon by this petitioner, is different than that used by the SWRCB in its updated water quality objectives? How is that incongruity resolved? And who identifies that discrepancy?
In another example, a water right petitioner pursuing Prop 1 funding for new water storage prepares their petition following the guidance provided by the Water Commission. Their climate change analysis is consistent with the Water Commission guidance, but they identify a suite of operational assumptions and include a series of reasonable and foreseeable future projects that differs from other Prop 1 applicants and even the future condition baselines used by other Divisions within the SWRCB. Again, who identifies these inter-project and intra-agency discrepancies and how are they to be addressed? These examples are not mere speculation; as such issues are emerging right now.
The same consistency problem would also apply to any of the other regulatory agency overseeing water-related projects in California. This includes the California Department of Fish and Wildlife, any of the Regional Water Quality Control Boards, State Lands Commission, Reclamation Board, and each of the federal agencies involved in water-related regulatory oversight (e.g., USBR, NOAA Fisheries, USEPA, USACE, FEMA, FERC, etc.). Each of these agencies would be faced with the same challenges.
As California moves forward with various new water projects, it is highly likely that emerging projects will continue to rely on their own set of assumptions and projected future conditions. In other words, no change from the status quo. But what are the long-term implications? As shown in the above examples, without the ability to uniformly address specific project impacts, in the context of the entire system, we lose the ability to ensure that what we are prescribing has a collective or cumulative benefit. Unfortunately, this has been the case for too many past decades.
We then continue to wonder why, after decades of effort, key elements of the system do not respond to many of our prescribed solutions as valuable facets of our natural environment, including listed species, continue to decline.
In the end, this lack of consistency will adversely affect both water users and the environment alike. All of which is very unfortunate since we have the ability, if we so choose, to avoid many of these adverse effects. While the inclusion of new future hydrology data represents the most technically challenging change in defining new future hydrologic conditions, it is not as daunting as many might think. Unlike several decades ago when the technology and science regarding our ability to establish and define new climatic and hydroclimatic thresholds was still in its infancy, we readily have that capability today. The remaining variables, including demands, accretions/depletions, operational rules, institutional controls, regulatory constraints, and physical limitations can each be well defined…agencies only require the fortitude to commit to do so collaboratively.
The challenge no longer resides in defining the key elements that make up a future hydrologic condition; the real challenge is having resource agencies actually do it – and then coordinate among themselves…
Does California need a singular, new, future hydrologic baseline? The answer clearly is an emphatic “yes”. Will it adopt one? Only time will tell, but at least we can now put all parties on notice of the administrative, technical, and institutional deficiencies, along with the potential legal risks, if we continue without one.
About the Author: Robert Shibatani, a physical hydrologist, is an international expert witness on reservoir-operations, climate change hydrology, flood damage reduction, and water supply development. He is on the Editorial Board of the Journal of Water & Climate (UK), International Water Association (IWA) Climate Change Task Force, and past Vice Chair of the Sacramento EWRI/ASCE. He is the Managing Partner & Principal Hydrologist of The SHIBATANI GROUP International and is the Founder and Chair of the international consortium, “Implementable Dam and Reservoir Development” (IMDAM) with corporate partners in the UK, Germany, New Zealand, Australia, Canada, and across the U.S. Robert resides in Sacramento, California. <robert@theshibatanigroup.com>
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