THE WATER BUBBLE: HOW SOUTHERN CALIFORNIA GOT INTO ITS PRESENT DROUGHT SITUATION

David Powell is a retired civil engineer who has resided in Pasadena for the past 37 years.  He is a 1949 graduate of Caltech.  His engineering career of nearly 40 years with Bookman-Edmonston Engineering was largely involved in the planning of public works projects, including project formulation, evaluation of alternatives (including economic evaluation), preparation of project reports, development of financing programs and related activities.

A few thoughts on California water issues from one who had a reasonably responsible forty-year career a a water engineer and water engineering executive.  I also can claim some familiarly with Pasadena, having lived in the city at the same address for more than forty years.  This is in addition to an earlier four year period while I was obtaining a degree from Caltech.

I am troubled by many aspects of the City's planning for meeting the water needs of those it serves.  To properly develop my concerns it is necessary to have an understanding of how we got into our present situation.

Let me preface this by saying I fully recognize the seriousness of the water crisis faced by Southern California.  This crisis comes about due to a combination of several factors, including:

(1) Failure to build the second stage of the conservation facilities necessary to enable the State Water Project to meet the amount of water it contracted to deliver.

(2) Failure to put in place a Peripheral Canal or its equivalent.

(3) Failure to face up to the loss of Colorado River water due to over-allocation of the available water on the Colorado River.

(4) Reduction in supply available to the City of Los Angeles from the Los Angeles Aqueduct because of greater retention in the local area of water from the Owens River basin.

(5) Other miscellaneous diminutions of supply from local and imported waters.

(8) The impracticability of a perfect operation regimen which actually achieves a full cutback in the first year of a drought, and which actually uses the last drop of stored water, just as the first drop of water from the drought-ending flood enters storage.

We are now a couple of years into a drought.  Whether of not it will reach the severity of the seven to eight year droughts that occurred twice in the prior century is not now foreseeable.  However, the recurrence of such a drought is to be expected at some time.  Also, the possibility of even more severe droughts needs to be recognized.

Background

At the Council meeting of February 16,Tim Brick (Pasadena's representative on the Board of Directors of The Metropolitan Water District of Southern California) made a presentation regarding the water outlook for California.  With some exceptions, I do not disagree with Mr. Brick on what he said.  What bothers me is what was left unsaid.   To properly develop my concerns it is necessary to have an understanding of how we got into our present situation.

California Water Plan

After World War II, it became obvious that California was headed for a water shortage, primarily in urban supplies in Southern California and agricultural supplies on the west side of the San Joaquin Valley.  So what was then the California Division of Water Resources undertook a state-wide investigation (in which I was a participant) to evaluate if California had sufficient water to meet full development needs.  It was concluded that then existing local water sources and then existing transfer facilities (including the Colorado River Aqueduct. Los Angeles Aqueduct and the federal Central Valley Project), supplemented by transfer southerly of waters from water rich Northern California which would otherwise escape to the Pacific Ocean, would be sufficient to meet foreseeable full development needs of California.

State Water Project

The first stage of a program to harness this excess water was developed and was originally referred to as the Feather River Project (now known as the State Water Project).  That Project was designed to provide some four million acre-feet per year, with the supply being derived from excess flows into the Sacramento-San Joaquin Delta from the watershed lying downstream from the most downstream dams on tributaries of the Sacramento and San Joaquin Rivers.

The State Water Project includes conservation facilities: Oroville Dam and reservoir on the Feather River; California's one half of San Luis Dam and Reservoir; and a portion of the facilities in the Sacramento-San Joaquin Delta.  San Luis is located off-stream just south of the Delta.

It also includes transportation facilities (those necessary to transport water from the conservation facilities to the areas of use).  Major portions of the transportation facilities were built to full capacity in the initial construction, and to a large extent those not so constructed initially have been subsequently increased to full capacity. However, the conservation facilities were initially built to supply only about 1/2 of the contracted State Water Project water supply.

The first stage of the State Water Project was planned to last until about 1990, when additional conservation facilities would be built to bring the State Water Project supply to full capacity,  This was to be achieved by additional storage in the Sacramento Valley, and by diverting water into the Sacramento Valley from the North Coast area (primarily the Eel River).  Such additional conservation facilities were never built, and there has been no enhancement over the original 1/2 capacity.  In fact, there has been diminution in available State Water Project supply by various encroachments thereon, with the principal one being the restrictions imposed on use of Delta channels for conveyance of water southerly.

Of the two million (in round numbers) acre-feet per year expected to be available available from the 1/2 capacity initial construction, one million acre feet represents Metropolitan's share.  The next largest amount (about 1/2 million acre feet per year) represents the share of Kern County Water Agency. with the remainder being used in the San Francisco Bay area, the Central Coast area, other areas in the Central Valley and Southern California urban areas outside the boundaries of Metropolitan.  As developed elsewhere in this document, the expected two million acre-feet per year amount has been diminished by various encroachments.

The full two million acre foot per year entitlement of Metropolitan in the completed State Water Project was derived as the sum of 1.5 million acre-feet per year needed to meet shortages estimated to prevail in 1990, plus 0.5 million acre feet per year to offset the reduction in supply available to Metropolitan from the Colorado River as a result of the over-allocation of the total flow of the Colorado.  It should be noted that the existence of this shortfall in Colorado River supply was known more than 1/2 century ago, when Metropolitan entered into its contract for State Water Project water.  At various times it has been suggested that Metropolitan should be doing something about this looming problems, but Metropolitan basically responded that there was no immediate problem, and Metropolitan could meet its needs.

Peripheral Canal

A major problem occurs as a result of the use of existing Delta channels for conveyance of water from the Sacramento River to south of the Delta.  This means of conveyance was used for the water from the federal  Central Valley Project and worked reasonably well.  However, with additions to the Central Valley Project and with construction of the State Water Project (also using Delta channels for conveyance), the Delta became overburdened and serious problems resulted.

To solve the problems resulting from the use of Delta Channels for conveyance, the construction of a Peripheral Canal (to bypass Central Valley Project and State Water Project water around the Delta) was proposed.   I believe that most technically trained water people consider that, had the Peripheral Canal been built, the present problems associated with use of Delta channels would have been largely solved.  About a quarter century ago, the proposal to construct the Peripheral Canal was placed before the voters of California.  For several reasons, there was a heavy vote against the Peripheral Canal in Northern California.  Unfortunately, there was not a sufficient vote for the Peripheral Canal in Southern California to overcome the Northern California "no" vote.  A primary leader in the Southern California's opposition to the Peripheral Canal was Pasadena's Tim Brick.  I am not sure whether Mr. Brick was on Metropolitan's Board at the time, but he was Pasadena's chief water adviser.  Without Mr. Brick's activities, we might well have had the Peripheral Canal in place for the last quarter century or so.

During the February 16 Council meeting, Mr. Brick was asked if what he now proposed was the Peripheral Canal.  He indicated no, this was a different facility.  I consider that answer to be disingenuous.  The current proposal mentioned by Mr. Brick is the functional equivalent of the Peripheral Canal. It differs from the Peripheral Canal in that it continues to use Delta channels for a portion of the conveyance, and it shrinks the capacity of the bypass facility.  To the best of my recollection, there was no mention of specific numerical values for capacities of the revised facilities.  The wisdom of both of these changes ought to be carefully evaluated.  Given the history of Delta problems (many of which can be characterized as unintended consequences) it would seem prudent to get the transfer water completely out of the Delta.  To build the bypass facility too small could result in a bottleneck which could impair the ability to develop new water supplies north of the Delta.

I strongly suspect that, had the Peripheral Canal been built in accordance with its originally planned design, the cost thereof would have been far less than the less satisfactory version currently proposed.

The editorial page of the March 20, 2009 issue of the Pasadena Star-News had several paragraphs dealing with the Peripheral Canal under the heading "Another View: Delta group has vision".  Unfortunately, there was no identification of whose view it was.  But it did contain the following interesting paragraph:

Researchers with the Public Policy Institute of California concluded last summer that a peripheral canal alone, rather than dual conveyance, would be best for the water supply and the Delta; that some water should be diverted to supply lines and the remaining water that flows into the Delta should not be pumped.

Safe Yield

Let me address the matter of the sustainable safe yield of the State Water Project, a subject which seems to be somewhat misunderstood.  The yield of a water supply system during a drought is the amount of water which can be drawn each year from a combination of water originating during the drought period, supplemented by water drawn from storage built up during prior wet years.  A drought period extends from the time that all supplemental storage facilities are full until all supplemental storage facilities are empty.  The critical drought period is that drought period which results in the lowest yield.  The critical drought period on any particular system depends on the fluctuations in annual water supply and on the percentage of the average annual water supply used.  In the case of the State Water Project, the critical drought period on which the sustainable safe yield was based consisted of a period of seven to eight years duration in the late 1920s and early 1930s.  A drought of similar severity occurred during the late 1980s and early 1990s,  Accordingly, any water stored to enable withdrawal of the full sustainable safe yield must be spread over a seven or eight year period.

To make up for the shortfall in water supply, Metropolitan has embarked on a banking program (not a part of the State Water Project) to store surplus water supplies in various surface and ground water facilities.  I believe the total capacity of such water banking facilities to be in the 2 to 2-1/2 million acre foot range.  Therefore the annual increment to Metropolitan's available sustainable water supply is some 0.3 million acre feet per year, which is not even enough to offset the annual loss in available Colorado River water.

There remain questions concerning Metropolitan's banking program for which I have not seen answers, including the following:

• How much evaporation loss is incurred on shallow reservoirs with large surface areas, such as Metropolitan's Diamond Valley Reservoir?

• What assurance is there that, in the future, sufficient surplus water will be available for refilling the storage included in Metropolitan's banking program during wet years?

• Metropolitan has the right to store (by exchange) State Project water in Lake Mead. What are the implications if Lake Mead fills and water is lost by spillage?  Whose water has spilled?

I have seen no documented studies of the extent to which the minimum available water supply to Southern California would be reduced with recurrence of a critical drought on the State Water Project, concurrent with a critical drought on the Colorado River.  I do not know whether such documented studies exist.  But I suspect that the shortfall would be worse than than the numbers which one hears bandied about today.  In fact, I would not be at all surprised to see a year of 50% or more cutback in overall supply to Southern California water users.

Another area which has not been adequately addressed is the problems associated with attempting to deal with a supply inadequate to meet needs.  Does one bite the bullet and limit withdrawals to sustainable safe yield each year, hoping that a more severe drought doesn't occur?  Does one try to draw on the project at rates greater than sustainable safe yield during wet years, running the risk of reducing the water available in the later years in a drought?  The solution that appears to have been adopted by those responsible for operation of the State Water Project is to try to withdraw water at rates in excess of sustainable safe yield, but to cut back at the first sign that we may be getting into the start of a possible critical drought (such as the current situation).  This means that we will have many instances when hindsight will show that we unnecessarily cut back.  I would like to see the specific criteria which govern the current mode of operation.

Wouldn't it be simpler to just develop the water supply necessary to meet our water needs, with a suitable cushion to provide for the unexpected?

Summary

In summary, I am troubled by the fact that this crisis was allowed to grow to this magnitude.  I disagree with the argument that this was a surprise act of nature.  The problems that exist had been well known but ignored for many years.  My second concern is the entire emphasis is on making do with inadequate water, while the expansion of the available water supply remains undiscussed.  In my view, construction of a Peripheral Canal or equivalent should be started  tomorrow, and the necessity of additional storage and diversion of Northern California water should be reevaluated and appropriate construction initiated.

Comments

[sinanju]

I've been under the impression that large infrastructure building in CA has been out of fashion since at least the time of Governor Moonbeam. It brings in more of those pesky humans, after all.

[Sam]

"Conservation facilities"!! That's a new one!