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In the Introduction to his text, Groundwater Hydrology, the late David Keith Todd offers a brief history of groundwater development from ancient times and groundwater theories dating back to Greek and Roman philosophers, whose theories ranged “from fantasy to nearly correct accounts” (Todd 1980).

An important step forward . . . was made by the Roman architect Vitruvius. He explained the now-accepted infiltration theory that the mountains receive large amounts of rain that percolate through the rock strata and emerge at their base to form streams. . . .

 

The French potter and philosopher Bernard Palissy (c 1510-1589) reiterated the infiltration theory in 1580 but his teachings were generally ignored. . . .
[(Todd 1980) footnotes and endnotes omitted, emphasis added]

In his own Introduction to the early U.S. text Hydrology, the section, “The Founders of Hydrology”, Oscar Meinzer (1942) credits Leonardo da Vinci (1452-1519) with having advocated the infiltration theory slightly before Palissy’s time, basing his theories on observations made when he was in charge of canals in the Milan area.

He notes the French Hugenot Palissy as the “inventor of enameled pottery and a pioneer paleontologist”. But, born in poverty, he was not educated in Greek or Latin, which may partially explain why his teachings about infiltration were ignored.

He began to observe nature, and he based his theories on his own observations. “I have had no other books,” he wrote, “ than Heaven and Earth, which are open to all.”
(Meinzer 1942)

Todd (1980) continues,

A clear understanding of the hydrologic cycle was achieved by the latter part of the seventeenth century. For the first time theories were based on observations and quantitative data. Three Europeans made notable contributions, although others contributed to and supported these advances. Pierre Perrault( (1611-1680) measured rainfall during three years and estimated runoff of the upper Seine River drainage basin. He reported in 1674 that precipitation on the basin was about six times the river discharge, thereby demonstrating as false the early assumption of inadequate rainfall [to support springs]. The French physicist Edme Mariotte (c 1620-1684 made measurements of the Seine at Paris and confirmed Perrault’s work. His publications appeared after his death, and contained factual data strongly supporting the infiltration theory. Meinzer once stated, “Mariotte . . . probably deserves more than any other man the distinction of being regarded as the founder of ground-water hydrology, perhaps I should say of the entire science of hydrology.” The third contribution came from the English astronomer Edmund Halley (1656-1742), who reported in 1693 on measurements of evaporation, demonstrating that sea evaporation was sufficient to account for all springs and stream flow.
[(Todd 1980) footnotes and endnotes omitted, emphasis added]

Todd dwells little further on these fundamentals of groundwater hydrology and one wonders whether that may be true for all such texts – ? If a student chose to skip the introductory history he might miss such key points as the general ratio of surface runoff to precipitation on a catchment.

Such a scenario might explain why California DWR staff and like-minded academics and nonprofits have all jumped on the bandwagon of Flood MAR [Managed Aquifer Recharge]. Not only does this approach target the smallest fraction of precipitation on a watershed/ catchment, it must necessarily target solely flood flows or risk compromising extant water rights.

All these experts focusing the attention of the California Water Plan on Flood MAR when the proportion of water actually “harvestable” is a small percentage of total precipitation on a catchment.  Strategic thinking?  Might they all be unconsciously stuck in the paradigmatic traps articulated in Figure vs Ground and Stream Networks vs Watersheds/ Catchments? It sure appears that they can’t see the catchments for the streams.

Background: I’ve been proposing what I now refer to as the Rainfall to Groundwater approach to DWR since 2009 and they refuse to give it a fair hearing, backing the more reactionary (to SGMA) Flood MAR approach in the California Water Plan Update 2018 – Public Review Draft. My January 21, 2019 comments on that are here, wherein I compare Flood MAR to a Rube Goldberg contraption relative to the much more elegant Rainfall to Groundwater catchment / natural recharge restoration approach.

I’ve added the below diagram, Surface-Groundwater Interactions, to the page, Surface-Groundwater Systems in a Holistic Water Cycle but we consider it here with respect to approaches to California water resources.. It’s a stylized, edited version of the Figure 1 conceptual diagram in Surface and Groundwater Interaction (Wright ed. 1980), published by UNESCO.

Click image to expand

Given SGMA, California agency staff and decision-making bodies have been beefing up their understanding of these interactions, which is commendable. However, the focus has been decidedly on baseflow interactions – also commendable, but not the whole story.

Additions to the diagram show the general sphere of influence or concern addressed in the case of a typical focus, represented by the Dec. 3, 2018 Water Boards’ Groundwater-Surface Water (GW-SW) Interactions Workshop presentation materials.  I only reviewed the meeting materials and available presentation pdfs (some had bad links) and all appeared excellent, but my distinct impression is that the only part of the system addressed was baseflow interactions.

Similarly, the Flood MAR approach addresses solely a small portion of direct runoff.

Rainfall to Groundwater covers a much greater portion of the system, as shown below.

But back to those basics – again Rainfall to Groundwater concerns a vastly greater proportion of the lands upon which precipitation falls than does Flood MAR, for example.

It seems our California DWR can’t recognize a solution unless it requires a major engineered component.

Perhaps the State of California Water Resilience Portfolio will be more open to exploring catchment/ natural recharge restoration approaches. I am submitting my synopsis to their public input process, trusting they will come to recognize that cost-effective water resilience fundamentally relies on restoring healthy catchments/ ecohydrology much more than on 20th century-type engineering schemes.

Heads up that a newly updated and refined Rainfall to Groundwater Executive Summary is available.

Verna Jigour, PhD.

 

Citations

Meinzer, O. E. 1942. Introduction. Pages 1-31 in O. E. Meinzer, editor. Hydrology. Physics of the Earth. Vol. IX. Dover Publications, New York.

Todd, D. K. 1959, 1980. Groundwater Hydrology. Second edition. John Wiley & Sons, New York.

Wright, C. E., editor. 1980. Surface and Groundwater Interaction. International Commission on Groundwater, UNESCO. Paris.

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