Before getting into the “meat” of this post, I want to alert the reader to the Rainfall to Groundwater Executive Summary report now available for free download.
California Department of Water Resources (DWR) deserves major complements on their final Water Available for Replenishment (WAFR) report, published last month. From the perspective of Rainfall to Groundwater there is one huge error of omission, but setting that omission aside for the moment, DWR has done an admirable job of quantifying and articulating water resources and surface water availability by hydrologic region.
Clearly DWR has compiled the data, but what is most impressive is how well they have organized and displayed it in ways that may be readily accessed and interpreted by all who need the information. Each region should find a wealth of data reflecting their own water resources. They may find the additional perspective comparing their own data to that of other regions helpful in better understanding their own circumstances (perhaps eliciting empathy/ envy for those regions differently endowed).
And then geographic spatial data geeks like me could spend hours comparing regional data pages, absorbing more about our diverse state from those “pictures” than the proverbial “thousand words”. The report not only serves its intended purpose but offers a geographic snapshot of the state unlike this author has ever seen before.
As for that huge error of omission, this is the assumption that natural groundwater recharge cannot be enhanced – an error I’ve been striving to bring to DWR’s attention for nine years now. And then there are some issues concerning their graphic portrayals of systemic relations that correlate with that large omission and reveal further errors.
This entire website is devoted to promoting understanding of how natural recharge may be enhanced and the Executive Summary offers a new shortcut means of assimilating the information. So I won’t even get into all that in this post. But WAFR’s otherwise excellent Figure 3 offers a ready means of conveying what adding Rainfall to Groundwater can mean for the recharge concept.
As noted in the Executive Summary, the reason the Rainfall to Groundwater Capacity bar is proportionately much higher than the others is an issue of scale. The spatial opportunities to restore historically degraded detention functions are vastly more expansive than are those for the engineered “Projects” and their diversion capacities. See the satellite image pf California on the California Case page or blog post 1, for example. The reason the Rainfall to Groundwater volume extends below the red bar for “Project(s) Diversion Capacity” is that the recharge functions of at least some, if not most, of those engineered structures could be accomplished – at much lower cost and more expansively – by the Rainfall to Groundwater approach.
WAFR Figure 1 has screamed out for my critique since I first saw it in the draft report. Below is that figure with my comments. Please note that the original WAFR Figure 1 does not show the land cover as pink – the green overlay just didn’t import to my software.
The visual emphasis of WAFR Figure 1 is decidedly on the engineered “active recharge” structures. While infiltration from a river is shown on the right, the relatively smaller area and fewer arrows indicating infiltration/ percolation from the river visually suggest that the river offers smaller contributions.
Two problems with that: 1.) there is no indication of bank storage along the river, nor its contributions to recharge, and 2.) recharge from the river extends up its entire length, so the total recharge volumes contributed by the natural river far exceed those of the relatively small, “point source” engineered recharge structures. This is another issue of scale. Hence my darker blue infiltration arrows along the entire length of the river (where they fit).
The point is that natural river/ stream systems offer far greater spatial opportunities for recharge. Our money would be far more wisely spent restoring the natural functions of our rivers and streams – allowing more room for floodplains and restored riparian zones that offer bank storage detention, as well as infiltration/ percolation functions and are self-maintaining.
Now, an excerpt from my comments on the Draft WAFR report, which were submitted just in time but, I later learned, were inexplicably routed to DWR archives – perhaps like my other efforts to penetrate their apparent “fortress” – and thus not posted on the DWAFR comments web page. They remain as applicable now as when I submitted them over a year ago:
I’m sure the good folks at DWR don’t intend it but this document appears to reflect engineers recommending more work for their engineering colleagues, along with the construction and heavy equipment interests they run with. Self- serving professional disciplinary bias! This is actually a profound economic/ fiscal responsibility issue, as it wastes public funds on expensive engineered systems that require ongoing funding for maintenance, whereas such costs could be significantly reduced with restoration and management of more natural or naturalistic systems. Or might it also reflect institutional laziness, as illustrated in the following example?
Over the pair of decades bookending the turn of the millennium, I consulted on several projects within the Arroyo Seco watershed, tributary to the Los Angeles River. Two of these were among the first watershed scale projects in the region and even the state as a whole. I developed the spatial analysis/ planning processes for the Arroyo Seco Watershed Restoration Feasibility Study and shepherded the Habitat Restoration component. Having developed logical planning analytical sequences for riparian and floodplain naturalization, and development of an overall water budget, as well as having traversed by foot much of the riparian-associated upper reaches of this watershed extending to 5,000 feet in the San Gabriel Mountains, I gained a good understanding of the watershed and potential restoration strategies to improve watershed functions.
Several smaller structures impede natural streamflow above Devil’s Gate Dam, though that is the best known outside the watershed. Above Devil’s Gate Dam lies the Hahamongna alluvial floodplain and wash, beneath which lies the Raymond Basin aquifer, adjudicated in the 1930s. Among the upstream structures is diversion infrastructure to channel flows into the percolation basins managed by the City of Pasadena to feed the aquifer.
As the City developed a master plan for the Hahamongna wash area, among the controversies was the proposed expansion of the percolation ponds, with incumbent loss of natural wash habitats for such species as the federally endangered arroyo toad. As I recall, the City was able to get some special dispensation regarding the toad, avoiding designation of Critical Habitat by USFWS in Hahamongna.
Among the hydrological reports commissioned by the City during master planning was one by Phillip Williams Associates (2000) that indicated that greater infiltration to the aquifer could be achieved through allowing the natural stream/ fluvial system to operate across the floodplain than that achieved through the diversion-to-percolation system. This is partly, or perhaps mostly because the engineered system requires continuous maintenance – removal of fines that rapidly build up in the artificial ponds, essentially plugging their infiltration functions. In a more natural fluvially-shaped system such impervious buildup is washed into discrete pockets, whereas most surfaces are episodically flushed of their fines, no human input needed.
I’m not privy to specifically how the City of Pasadena reacted to the PWA 2000 report, but I do know they subsequently commissioned other studies to arrive at the results they wanted – justification for more percolation ponds to justify more income to the City for their percolation efforts. My understanding is that, despite the knowledge that greater infiltration/ percolation to the Raymond Basin aquifer could be achieved much more efficiently, the percolation basins offer the City a means of *measuring* how much they are contributing, thus justifying payment for their services.
Considering the value of water in California and especially in the context of at least the intent, if not the letter of SGMA, such behavior seems unconscionable. I recall the City’s facile explanations including the long history of adjudication of the aquifer, how negotiations were so complex that any tweaking could derail the entire agreement. My response to that is that this is all just words on paper – far easier to adjust than the function of natural systems, especially given the increasing value of water. Another concern expressed was the ease of measuring percolation pond functions. But there are absolutely ways of measuring and monitoring the function of natural systems – step up to the 21st century, ecohydrology, systems dynamics and nonlinear math. The failure to move beyond 20th century thinking in both the legal and mathematical modeling realms represents laziness that does a disservice to the City’s constituents, as well as all who draw from the Raymond Basin aquifer. I know that SGMA involves a separate process for adjudicated basins but I do hope that these issues don’t fly under DWR’s radar with respect to such basins.
Furthermore, these same issues apply to all the non-adjudicated basins for which DWR recommends the two engineered direct recharge methods. Having grown up in and lived much of my life in Santa Clara County, the direct recharge methods proposed are quite familiar – reflecting the numerous percolation structures developed by the Santa Clara Valley Water District, which absolutely merit credit for stemming the tide of land subsidence in the valley. The [DWAFR] Figure 1 structures look quite at home in such urbanized floodplains. But does that configuration represent the best response for all groundwater basins??? Not all are urbanized to the degree of Silicon Valley.
One final point on DWR’s description of direct recharge structures is that they appear devoid of vegetation. Another story from my professional history – early 1990s I worked as planner/ botanist on a Master Plan for the San Bernardino Valley Water Conservation District. I learned then that the District was somewhat singular in allowing vegetation to grow in and around their spreading basins, which comprised a relatively small portion of the over 3,600 acres of alluvial scrub they manage(d?) on the Santa Ana Wash, where the Santa Ana River disgorges from the San Bernardino Mountains. I’m unclear whether they have continued to manage those basins since completion of the Seven Oaks Dam just upstream.
In conversations with the late Peter Rusher, District Manager throughout most of our work, I gleaned the impression of an agency staffed with crusty old-timers whose management styles were driven more by direct observation/ experience than by the latest trends among the water engineering cognoscenti. He told me that the District’s engineers believed they got better performance from their basins by allowing vegetation to grow. Having surveyed significant portions of the District’s 3,600 acres for the most diminutive of the two federally endangered plant species there, I can attest that vegetation on the spreading basins was far from pristine alluvial scrub, with much of it being quite weedy. So while it doubtless offered some habitat functions for generalist and wetlands wildlife species, it would be a stretch to call them habitat features of any great significance.
But especially given my subsequent doctoral studies concerning the effects of root systems and old root channels on water flow through vadose zones, combined with understanding of how organic matter improves the infiltration and percolation functions of any soil texture, I can readily see how the District’s no-fuss system could easily surpass the functions of the biology-free recharge structures envisioned by DWR.
All those watershed functions and more operate on natural stream/ floodplain systems, so while [DWAFR] Figure 1 acknowledges infiltration from natural streams, DWR’s complete omission of restoration of natural stream/ floodplain systems among its recharge methods subsequently described in the document simply screams of DWR’s decided professional bias and blind spot with respect to opportunities to better sustain groundwater! These errors of omission ultimately constitute irresponsible policy development.
Moreover, I assert that DWR’s bias is not simply due to accepted quantitative engineering models (that have long conveniently simplified out interactions with bio/ecological systems in favor of “approximations”), but reflects an overall reductionist paradigm, wherein figure is elevated above ground. Specifically, DWR tends to view watersheds, when they consider.them at all, as stream systems, ignoring the uplands that comprise, by far, a much greater proportion of the land upon which precipitation actually falls. This also seems to reflect professional bias, given that during the 1990s Clean Water Act push to stem nonpoint source pollution a common refrain was to “start at the source”, meaning the uplands, not the lowlands to which it all drains. I do understand that this is partly a legal bias since, prior to SGMA, only surface water has been regulated, so the legal focus has been on the rivers and streams.
Verna Jigour comments on DWAFR submitted March 10, 2017
Pease see my pertinent graphics on Stream Networks vs Watersheds/ Catchments for more on this last issue, above.
Another issue of bias that hadn’t crossed my radar until I read the Mercury News story cited/ linked on Surface-Groundwater Systems in a Holistic Water Cycle (near page bottom in light violet box) is that of confirmation bias which actually may be the most applicable to DWR’s failure to recognize or even consider the Rainfall to Groundwater approach.
I won’t argue that the final WAFR hasn’t met the statutory requirements of Water code 10729 (c) noted on WAFR page 5 , with respect to “available information”? But note the paragraph below.
Methods of making water available include a portfolio of water management actions: surface water development (including stormwater), water conservation, recycled water, desalination, and water transfers. All of these methods can help make water available for groundwater replenishment by either increasing water supply directly or reducing demand on existing water supplies.
WAFR page 11
So, while elsewhere WAFR purports to concern solely “surface water” available for replenishment, that paragraph shows they are including other options in the mix of “available water”. Then why not the approach encapsulated by Rainfall to Groundwater???
Also, consider Text Box 2. Flood-MAR: Using Flood Water for Managed Aquifer Recharge on that same page 11. The box notes that Flood-MAR includes the following public benefits:
• Flood risk reduction.
• Drought preparedness.
• Groundwater replenishment.
• Ecosystem restoration.
• Aquifer remediation.
• Working landscape preservation and stewardship.
• Climate change adaptation.
These same public benefits would be offered by the Rainfall to Groundwater approach! In contrast, it requires no diversion of surface waters.
I’ve been trying to get this approach through DWR’s impermeable membrane since 2009. Had they begun considering the issue then, this would have become “available information”. Bad enough that they have consistently ignored reasonable input from a state citizen. But when that input has the potential to benefit many stakeholders in ways beyond what their engineered solutions offer, it just seems wholly irresponsible not to even give it a second look. One could claim “obfuscation” but I actually don’t believe it is that nefarious.
DWR certainly can’t claim there isn’t scientific support for the Rainfall to Groundwater approach, given that I provided them with 100 pages of pertinent topical bibliographies supporting it as they began to implement their SGMA responsibilities. But then they probably routed that file to their “archives”, like they did my DWAFR comments. Just sweep it under the rug, eh?
Furthermore, DWR’s call for “Innovation” on the WAFR news release page, seems laughable when the agency appears so unable to “think outside the box” [ Think Outside the Basin ] beyond solely engineered solutions to the problem of groundwater sustainability.
At least WAFR, page 19 notes:
GSAs can and should consider the water available from other methods.