Residing in Kern county, in the State of California, where the entire flowage of the Kern river is applied to agricultural lands on what is known as the Kern River delta, to a large extent under my personal supervision, I can state as a fact that a very perceptible effect is observed upon the low-water flow of the river since the exclusion of sheep from the forest reserves covering the river’s watershed. I need not go into a process of reasoning to account for a fact that is so obvious and so well-known. It is not claimed that the aggregate discharge of a river is increased by the growth of timber or vegetation, but it is demonstrated that the run-off is more gradual and is prolonged through a greater length of time. That is to say, the forests and vegetation serve the same purpose as artificial reservoirs, made by dams or otherwise. Also it is evident that if the ground surface is protected by timber or vegetation from erosion, artificial reservoirs are protected from being quickly filled up by silt from the mountain slopes, and disastrous torrents are prevented.
According to daily measurements of Kern river, during the period of seven years from 1899 to 1906, after the establishment of the national forests, we find an increase of minimum flow from 86.22 feet to 222.06 feet—an increase of over 50% taking place in the seventh year. Through this steady and gradual increase, the area of lands under irrigation was increased from 130,000 acres in 1899 to over 180,000 acres in 1906.
Also, according to the statement of Elwood Mead, in his report of irrigation investigations in California in 1901, there seems to be a conclusive demonstration of the favorable effect of forests on the watershed of a river on the low-water run-off. A case in point is the difference between the run-off of the two branches of the Yuba river. The North Fork, being heavily timbered, furnishes 75% of the low-water flow, which is supplied from only one-tenth of the total drainage area—the watershed of the South Fork being comparatively bare of timber. Mr. Mead summarizes his conclusion on this subject in the following language:
It appears that the solution of the problem of a storage of flood waters is not in the retention of a small percentage of the storm waters behind dams, but in applying storage over the entire watershed by the systematic extension of forest and brush-covered areas. …
– Grazing on the Public Lands address by H. A. Jastro at the 1908 Conference of Governors on Conservation of Natural Resources called by President Theodore Roosevelt (McGee 1909), emphases added
Among the striking aspects of this excerpt and the rest of Jastro’s statement is that these relationships, “so obvious and so well-known” were completely forgotten within a few decades, along with widespread comprehension that conservation of natural resources represents a true national security issue.
Observing, in another part of his statement, that establishment of the national forests had stemmed
. . . the range wars and feuds between cattlemen and sheepmen in their struggles to retain possession of certain areas or ranges that have been almost blighting in their effects on the region in which they occurred, all of which is to be attributed to absence of regulation. But within the national forests, with their forces of rangers to see that each one keeps to his own range; that no one man, no matter how great or rich or influential, trespasses upon his neighbor, be he ever so small; and thus insuring to each a portion of the range upon which he is quite as secure in his tenancy as if he owned it in fee simple–these troubled times have passed away. Peace reigns now where not many years ago sheep camps were almost nightly shot up and stock of all kinds killed in wanton and criminal disregard of law and decency.
– H. A. Jastro 1908, as cited above
Might Jastro have imagined how the “sagebrush rebellion” against federal management of grazing lands would lead to armed insurrection in the 21st century? Perhaps, since he acknowledged some controversy over federal land management persisted during his time. Yet his statement makes clear that his conclusions were informed by prominent discussion among leaders at annual meetings of the American National Live Stock Association. The memory of recent “range wars” was then too fresh to be forgotten by members of that group.
But how many current rangeland managers, moreover water agencies make the connection between watershed land cover and summer baseflows, fed by groundwater?
By then “former” California Governor (1903-1907), George Cooper Pardee, MD, an ally of President Theodore Roosevelt, noted in his address at that 1908 Conference of Governors,
. . . In order that these streams may be made to yield as great a low-water supply as possible, the President has very wisely made national forest reserves along their headwaters. . . .
– Ex-Governor Pardee (McGee1909)
Again, recognition of that relationship between watersheds and baseflow has been essentially lost among California state and local government agencies, including water agencies. If Governor Brown or his esteemed associates were aware of it they might have directed the Department of Water Resources to address watershed relationships when they developed the CASGEM Groundwater Basin Prioritization maps.
If state legislators were aware of it they might have ensured that Proposition 1 funding for “watershed restoration” applied to more than solely Sierran mountain meadows (aka floodplains). Was that correlation meant to support only those drawing from the state water projects? What, no other California watersheds matter???
What especially caught my attention was Dr. Jay Lund’s comment regarding proposals to fund mountain meadow restoration:
I don’t think there’s a [strong connection] there, because there’s often a big reservoir that redoes the timing, so the benefits that [you] actually see when you get down there for the water people are really pretty small.
I cannot let that go without adding my own comments.
Compared with the enormous costs associated with all engineered approaches to water storage, the relatively nominal costs of meadow restoration seem a good bargain for water agencies – you expand the effective storage capacity of those reservoirs at a *fraction of the cost* of engineered “fixes”.
So why wouldn’t that be a sound investment for any water agency? I could hardly agree more with Sierra Nevada Conservancy Executive Officer Jim Branham’s comments during that meeting’s panel discussion that the Sierra Nevada gives far more to California water resources than it receives in return for those benefits.
Furthermore, one of the heartening results of research conducted during the recent multi-year drought on the Southern Sierra Critical Zone Observatory (CZO) in California’s Kings River Basin is that winter evapotranspiration from cold high elevation areas did not increase during the drought, acting as a kind of buffer against other drought impacts. Those results offer further support for Sierra mountain meadow restoration, since such meadows can temporarily store snowmelt from those high elevations, prolonging the runoff period and expanding effective reservoir capacity.
That was not even the most profound result from that research, but it’s too much to go into here. I recommend that anyone interested in learning more about these results view Dr. Roger Bales’s lucid December 2017 American Geophysical Union Nye Lecture, “Making up for lost snow: lessons from a warming Sierra Nevada”, video linked here. The whole story only further bolsters the importance of funding broad-scale watershed restoration in the Sierras, well beyond the meadows/floodplains – in ways that affected water agencies should be able to grasp.
Despite Dr. Lund’s dismissal of the value of watershed restoration above reservoirs to water agencies, it’s clear that at least some among us have recognized the link between forests and downstream water resources for more than a century. Though even I question the veracity of the seemingly rapid improvements in baseflow attributed to establishment of the national forests by H. A. Jastro, above.
But as valuable as mountain meadow restoration may be, the total potential storage area/volume there represents just a fraction of the potential offered by vast areas of the state that mostly do not lie upstream of reservoirs and may not be fed by snowmelt, but only become increasingly important as climate change decreases snowfall in California.
These are the nonnative annual rangelands upstream of most overdrafted California groundwater basins whose detention storage functions have been severely degraded through historical land uses. Since I’ve developed this entire website as a synopsis of this approach and encapsulated it in my first blog post, Water Storage & Water Available for Replenishment/ Recharge: A Promising Marriage, I won’t reiterate it here, but encourage you to explore Rainfall to Groundwater pages as they may call to you.
I’ve done my best to offer a summary on this site, but those who want to truly understand and implement the approach are advised to consider my proposed Learn, Apply offerings.
McGee, W. J., editor. 1909. Proceedings of a Conference of Governors in the White House, Washington, D.C., May 13-15, 1908. U.S. Government Printing Office, Washington, D.C.