Who
Should Get the Water, when push comes to shove?
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I wonder if they'll take 213 pounds of whelks for an acre-foot. of water. |
This post series encourages stakeholders, by becoming as knowledgeable as possible in a very short time, to vigorously participate in the design of their water futures, which are destined to become closely monitored, metered, and regulated by agencies both appointed and elected. Need to know includes such basic as how water is measured (acre-feet as well as gallons), how geography is delineated for water accounting, what aquifers or water-basins are, what are the sources of all water supplied to Californians, who determines allocations and use, and more.
Long-term design is most likely to successfully meet all stakeholders' goals when based on science, inclusive demographics, as well as accounting for and balancing the needs and desires of specific interest groups like agribusiness, environmentalists and planners.
We
focus on the Central Coast of California. The
conflicts of interests with the greatest impact on individual water
futures in
Santa Barbara County is that of sustainable water use and the California
agricultural lobby, with groundwater issues pivotal. The new water regulatory environment outlined by
Governor Brown, with conservation measures ordered for urban users of a
25%
mandatory cut in water use, still excludes specific regulations for
agriculture, though agriculture accounts for 80 % of water use in
California. The Central Coast, though climatically more desert than tropic, is considered the breadbasket of the
world, but is not a natural world wonder but an intensely engineered one.
The legislation passed in September of 2014 specifies that local agencies need to develop plans for groundwater use that can be tailored to regional needs and conditions.:
The legislation prioritizes groundwater basins that are currently overdrafted or at risk and sets a timeline for implementation:
- By 2017, local groundwater management agencies must be identified;
- By 2020, overdrafted groundwater basins must have sustainability plans;
- By 2022, other high and medium priority basins not currently in overdraft must have sustainability plans; and
- By 2040, all high and medium priority groundwater basins must achieve sustainability.
No immediate conservation measures were mandated for agriculture. Simultaneously, throughout the Central Valley, more wells are being dug deeper and at greater cost by those who can afford it to meet dwindling supplies of water for their purposes. Similar pictures reflect water scarcity drilling frenzy and groundwater depletion in Northern India, Syria, Saudi Arabia and the US. This is a water arms race, where he and she who can drill deeper survive longer while land is
reported
to be sinking half an inch a month and groundwater levels appear to be
sinking faster in the Central Valley than anywhere else in the United
States, according to a recent U.S. Geological Survey.
Consider the example of the
City and County of Santa Barbara, iconic of the good life
The City of Santa Barbara, to use
one specific example used for the purpose of limiting the complexity of
the water supply and demand issues to one relatively simplified ,localized
example for possible better understanding of how water supply and demand work
in most regions of California, depends on five different water supplies to meet
local demands: Local Surface Water, Local Groundwater, State Water, Recycled
Water, and Desalinated Water. Each of these will be addressed below to evaluate
how they might or might not meet SB community demands for clean water.
Under normal weather conditions
average water use by Californians is supplied 70% from surface water
supplies (rivers, lakes, stored water such as reservoirs and canals) and 30%
from groundwater supplies, stored in natural geological structures called
aquifers. During extended drought the average user draws on groundwater
supplies for 80% of water used. In some regions, such as the Central Coast,
almost 100 % of the water supplied is from groundwater.
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Groundwater
basins are prioritized under the new sustainable water legislation
according to level of concern for risks of depletion, subsidence, and
saltwater-intrusion. | | | | | | | | | | |
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Prioritization studies suggest that several regions are at risk for supply exceeding demand: specifically the Cuyama and San Antonio regions.
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Most
estimates of future supply of water are based on data that is sketchy,
such as that for groundwater reserves, assumptions about use, which may
be accurate or may not, and weather predictions, which under the
condition of Climate Change uncertainty, makes predictions regarding
future supplies porblematic.The above line graph predicts that for three out of the five detailed water accounting units (DAUs, see below), supply may be just barely met in 2040. |
Fundamentals
When speaking of large water quantities, the unit of measure is the
acre-foot or acre-inch, the amount of water required to cover one acre either
12 inches or 1 inch. Most Americans are familiar with gallons, so to get an
idea of the large quantities used to supply water to a region or for
irrigation, stakeholders who want to speak the water world language, need to
become comfortable with both. One-acre-foot is 325,851 gallons; an acre-inch is
27,154 gallons.
Putting Stats into a Context
The average household in this County uses between 30,000 to 90,000 gallons
of water a year. According to
Wikipedia,
"A 2000 study of a sampling of 735
California homes across ten
water districts found that the
weighted
average annual
total
water use of these
homes was 132,000 US gallons (0.41
acre.
ft) per year or 362 US gallons (0.00111
acre.
ft)
per
household per day."
The average
per capita use of water in the city of Santa Barbara is
130 gallons per day, which reflects current conservation practices, with Goleta using
less and Montecito about triple SB City residential use. These data are
supplied as basics for water literacy in our region. On the average, at least
half of local domestic water use is for outside purposes, including but not
restricted to landscaping, which is particularly important in Montecito.
About half of the water used indoors is for bath-shower and toilet.
Supply-side
The County contains four principal watersheds: the Santa Maria, which includes
the Cuyama and Sisquoc watersheds and covers 1,845 square miles; San Antonio Creek that covers 165
square miles; Santa Ynez that covers 900 square miles; and the South Coast, which is comprised of 50
short, steep watersheds extending from the ridge of the Santa Ynez Mountains to the Pacific Ocean. Four major
rivers drain these watersheds: the Santa Maria, Sisquoc, Cuyama, and Santa Ynez. Rainfall is
variable, with stream flow a function of rainfall. Accounting units are not geographically the same as watersheds, see below for accounting. Most avocados and 75% of nursery and hot-house crops and plants are raised in the South Coast watershed area, with water supplied from groundwater and surface water supplies including Cachuma, Gibraltar, and Juncal Dams (under normal conditions, which exclude the present extended drought). Wineries are scattered throughout the county. (blue on map below)
Under normal weather conditions
average water use by Californians is supplied 70% from surface water
supplies (rivers, lakes, stored water such as reservoirs or Lakes such as Lake Cachuma or Gibraltar Reservoir, along with whatever is present in canals) and 30%
from groundwater supplies, stored in natural geological structures called
aquifers. During extended drought the average user draws on groundwater
supplies for 80% of water used. In some regions, such as the Central Coast,
almost 100 % of the water supplied is from groundwater. The state allocates but does not always supply what is classified as surface water.
Consider the Other Suppliers
Surface Water: Lake Cachuma is SB’s primary source of surface water, though recharge is from rain and other sources. As of Aug 25, 2015, 40,751 acre feet are stored, according to the Bureau of Reclamation, which is 21.1 % of capacity storage. On an average annual basis, Lake Cachuma provides approximately one-quarter of the water used in the Central Coastal Region and 80 percent of Santa Barbara County’s
water supply.
State Water: For
2015 SB Co requested 45 486 acre-feet from the State Water project and was
granted
6823
AFY, or 15% of the water
requested. The ultimate source of all water for the State Water Project
is the
Feather River,a tributary of the Sacramento River. State water's largest
reservoir is Lake Oroville, with a water capacity of 3.5 million acre
feet. This Au
gust 2015, Lake Oroville is at 25% capcity, or about 890,000 acre feet. Santa Barbara County is entitled to 45,486 AFY.
, stored in the San Luis Reservoir. more at:
http://www.pacbiztimes.com/2014/02/07/tri-county-cities-scramble-as-state-cuts-water-deliveries/#sthash.k3qG3sjC.dpuf
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Under conditions of extended drought state-wide, such as we
are now addressing, State Water supplies tend to dwindle to almost nothing,
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Recycled Water: The City's Recycled Water Project recycles
approximately 800 acre feet of treated wastewater each
year.The cost per acre foot of recycled water is
approximately $1,200. To put this figure into perspective: Central valley water costs farmers anywhere from $500 per acre-foot up.
Desalinated Seawater : Santa Barbara's desal plant was constructed in 1991 and deactivated after plentiful rainfall made operation un-economical. The capital costs to reactivate the plant with a capacity of 3,125 acre-feet per year1 (AFY) are estimated at $55 million. Annual operating costs are estimated to be about $4.1 million at full production (for 3,125 AFY of water supply), and about $1.6 million in standby ready-state mode. Planned delivery of desalinated water is for 2016.
None of the above will meet the demands of residents in SB County.
The Biggest Source and Issues for Groundwater
During extended drought conditions such as we are dealing with today, August 30, 2015, ground water is the only source on which water users in the Central Coast can rely.
Groundwater: Although there are many, to a large extend unclassified and unmonitored groundwater basins or aquifers on the central Coast, the major ones are increasinglu understood and monitored. The major South Coast Groundwater Basins include: Carpinteria, Montecito, Santa Barbara, Foothill, and the Goleta
Groundwater Basins. The major groundwater basins within
the Santa Ynez River Watershed are, from east to west: Santa Ynez Uplands,
Santa Ynez River Alluvial, Buellton Uplands, Lompoc Uplands, Lompoc Plain, and
Lompoc Terrace Basins. These basins are adjacent to the Santa Ynez River and
lie between the San Rafael Mountains to the North and east and the Santa Ynez
Mountains to the South. Each basin is affected to some extent by water rights
agreements and Cachuma Reservoir operations. Primary among these is the Water
Rights Order 89-18 and the 2000 Biologic Opinion from the National Marine
Fisheries Service.
Water use within the Santa Ynez
Uplands Groundwater Basin is primarily for agriculture though there is also
urban use within portions of the basin supplied by Santa Ynez Water
Conservation District ID#1. The most recent report, dated 2014, by SB county agencies
indicates how water levels in all major basins have changed according to agency
calculations.
http://cosb.countyofsb.org/uploadedFiles/pwd/Water/WaterAgency/Status%20Report%20on%20Groundwater%20Basins_Final2.pdf
Geographical Accounting Units
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The DAU is the geographical accounting unit for water in a specific area. This concept is useful largely for regulatory and insights, based on diverse studies, with diverse purposes. the stakeholder needs to attend to who reports what and why.
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To summarize the last three posts, if stakeholders want their water futures to match their needs and desires for how water is accessed and distributed, they need to become knowledgeable and vitally active.