Title: Water Use
1Water Use
Source PBS Television (http//www.kteh.org/cadill
acdesert/episode4d.html)
2Water Use
- Water should always be allocated to the highest
and best beneficial use. - There are always allocation choices, and what is
the most beneficial use for a given unit of water
is a subjective issue.
3Water Use
- What do we mean by use? It depends on the
semantic context. - Writers commonly interchange use, demand and
consumption, sometimes confusingly. - Use as in demand the volume of water withdrawn
from a water delivery system or directly from a
natural source by a particular entity in a
particular unit of time.
4Consumption
- Consumption in the personal sense - as in volume
of drinking water (e.g. 2 l per day). - Consumption in the household (etc.) sense - as in
volume of water recorded daily on a household
meter(e.g. 1600 l per day). - Consumption in the hydrological sense - as in
volume withdrawn from a water body that is not
returned to that body.
5Consumptive uses and withdrawals
- Hydrologists talk of consumptive and
non-consumptive uses of water. - Hydrologists also talk of withdrawals and
in-stream uses. - Consumptive uses require withdrawals, but not all
withdrawals are consumptive. - In-stream uses are non-consumptive and require
the water to be used in-situ within the water
body. - A special class of in-stream uses are often
termed environmental water demand.
6In-stream uses
- In-stream uses are those that utilize water
in-situ as it resides in or moves through the
water body itself. - Examples include navigation, wildlife protection,
scenic values, recreation (e.g. rafting), waste
dilution and assimilation. - In many water bodies, minimum in-stream
requirements are specified which may have highest
(inalienable) priority within the water rights
system.
7Waste disposal
- Waste disposal is a significant and common use to
which rivers, streams and aquifers are put. - How much waste can be safely handled depends on
many factors including water body ambient quality
and capacity to dilute/neutralize, as well as on
waste volume and concentration.
8Non-consumptive withdrawals
- Some water uses merely borrow the water for its
mechanical or thermal properties and release it
back to the body close to the point of
abstraction. - Hydropower is the classic example of a
non-consumptive withdrawal. - Many cooling systems return only part of the
water withdrawn due to evaporative losses.
9Temporary withdrawals
- Although not consumed, temporary withdrawal may
physically or chemically alter the water in the
process (temperature, contamination). - The rerouting of water may create major
environmental changes. - The returning water may have different properties
as a result of its withdrawal.
10Hydropower withdrawals
- Example Hydropower generation
- Water is usually dammed then rerouted through a
tunnel and turbine. - Damming changes water quality (temperature,
oxygen, sediment load). - The dam is a physical barrier to fish,
navigation, etc.
11Consumptive withdrawals
- Water is withdrawn for uses which ultimately
result in its evaporation and return to the
beginning of the water cycle as atmospheric vapor
(classic example is irrigation water). - Water is withdrawn and transferred to a different
water body via a variety of mechanisms (e.g. in a
bottle, in a product, via a pipeline, through
seepage, etc.). - Not all consumptive withdrawals are actually
evaporated and are partially returned to the
originating body somewhere in the system.
12Complicating Factors
- Transferred water that is not evaporated must be
added to the water balance of the water body into
whos system it is released. - Many withdrawals are intra-watershed with respect
to a given water body and any unevaporated water
released back into the system must be accounted
for (these are called return flows). - Classic return flows include irrigation water
seepage losses and runoff and sewage effluent
discharge.
13Understanding water use
- Disaggregated data is very useful to water
planners. - Effective demand forecasting, drought management
and water conservation planning require
comprehensive information on how customers
actually use their water. - Such information is also a key element of billing
wastewater treatment fees.
14Accounting for water use
- Measuring demand requires using pipeline meters,
flow sensors or pumping data. - In urban areas, water meters allow providers to
bill users based on volume. - Assigning codes to accounts allow providers to
aggregate demand by type of user. - Further disaggregation of demand by type of use
requires more detailed information that requires
some form of audit study.
15Urban demand for water
- Depends on the character and relative number of
customers in different classes, and their water
use habits. - Urban customer classes are usually industrial,
commercial, governmental, residential (single
family, multi-family), landscape. - A key concern in many urban areas is the
proportion of demand uselessly lost during
delivery as opposed to used productively.
16Unaccounted for Water
- Distribution system losses evaporation, seepage,
leakage from mains upstream of customer meters
(ruptures, breaks), leaks from valves, hydrants
and meters, leakage and overflow from tanks and
reservoirs, backwash, etc. from treatment plants. - Metering and other losses source meter errors,
supply meter errors, unauthorized consumption
(illegal connections, illegal bypasses),
meter-reading errors (temporary,
self-correcting), unmetered flushing and
fire-fighting use.
17Accounted for losses
- Customer losses (note that these will be billed
as legitimate uses where meters are installed)
broken pipes, leaking valves, leaking faucets,
bleeding toilet tanks. - Customer inefficiencies (note that these will be
billed as legitimate uses where meters are
installed) unnecessary or inefficient water use
practices (e.g. irrigating in a rainstorm).
18Residential water uses
- Generally landscaping (33), interior use (66).
- Interior uses - toilets (36), bathing (28),
laundry (20), misc. faucet use (13),
dishwashing (3). - California average is around 120 gallons per
capita per day (gcd), 80 gcd inside, 40 gcd
outside.
19Industrial and commercial
- Indoor process (industry-dependent), HVAC
(boiler make-up, evaporative cooling),
sanitation, worker hygiene, janitorial, fire
control, catering. - Outdoor irrigation, dust-suppression,
hosing-down, fire control. - Industrial demand is highly skewed and
frequently, 90 of the total use will be
accounted for by around 10 of the users within a
given distribution system.
20Agricultural and Public Sector
- Agricultural Irrigation, processing (sluicing,
grading, washing, etc.), hosing-down, livestock
watering, worker and animal hygiene, pesticide
applications, etc. - Public Industrial and commercial-type uses (as
appropriate), irrigation (parks, dividers, etc.),
water main and sewer main flushing,
fire-fighting, swimming pools, water feature
make-up, etc.
21Agricultural demand for water
- The demand for agriculture is principally a
function of area of land cultivated, crop types,
type of farming system, irrigation technology,
irrigation efficiency, climate and soil type. - In CA, around 9 of irrigated agriculture is by
drip, 24 sprinkler and 77 furrow or flooding.
22Environmental water demand
- Wild and scenic river requirements
- Fishery and wildlife preservation
(freshwater-saline water balances, temperature
regimes, turbidity levels, flooding patterns, and
current velocities and directions) - Recreational needs.
23Demand variations
- Demand can vary by time of day, day of the week,
season, and over a period of years in response to
trends in water use, population, etc. - Agricultural demand is highest during the day in
the summer growing period. - Urban demand is highest during the day on summer
weekdays.
24Demand variations
- Environmental water demand is generally very site
specific. - For example, in California it is highest during
the Fall, coinciding with the Chinook Salmon run. - It depends on when the critical conditions occur
for endangered species life-cycles and habitat
preservation.
25Conflicts over water
- In-stream v Consumptive withdrawals e.g. over
Sacramento/San Joaquin salmon v irrigated farm
production. - Consumptive upstream v. consumptive downstream
e.g. Guadalupe River, TX., Jordan River, Tigris
Euphrates. - Instream v Non-consumptive withdrawals e.g. CA
hydroelectric dams v migrating fish.
26More irrigation
- Currently, irrigated agriculture produces around
40 of the worlds food supply and uses about 70
of water supplies. - World food production will only keep pace with
population growth if more irrigation occurs, thus
requiring more water to be allocated to
agriculture.
27Growing cities
- By 2025, the number of world cities with over 1 m
people will double to over 600. - The vastly increased demand for high quality
water for domestic, commercial and industrial use
will cause even greater allocation conflicts
between farmers and the cities and
environmentalists.
28Water ownership
- Water laws and regulations have grown out of
complex water use situations such as the conflict
over water during gold rush times in the Sierra
Nevada.
29Who owns water?
- Water in nature is generally usufructuary -
individuals only have the right to use it, not to
own it. - In most cases, water is owned by the nation or
the state, which recognizes or assigns an
individuals rights to beneficially use the
water.
30Riparian rights
- These are the rights to use water as a result of
the ownership of property that abuts a natural
water body. - The riparian water right is said to be part and
parcel of the land, unless expressly and legally
excluded from the land title.
31Riparian rights considerations
- All riparian rights are considered equal.
- Riparian rights are often unadjudicated (they are
not quantified). - Riparian rights are usually superior to all other
water rights. - Sub-division of riparian lands or acquisition of
adjacent non-riparian lands creates tricky legal
issues.
32Riparian rights example
- Which lands are riparian lands?
- ____________
- Which lands are non-riparian lands?
- ____________
- Could Farmer B take more water if she acquired
land D?
A
River Blue
C
E
B
G
D
F
33Appropriative rights
- These are the rights to divert and use a specific
quantity of water for reasonable beneficial use
in a specific non-riparian location. - They are governed by the first-in-time,
first-in-right doctrine. - Most appropriative rights systems use the use-it
or lose-it principle.
34Appropriative rights adjudication
- In theory, in times of scarcity, senior rights
holders get priority for available water
supplies. - In practice, courts have used the public trust
doctrine to give junior rights holders an equal
share during drought years.
35Appropriative rights history (Ca)
- The CA. Supreme Court codified the appropriative
rights doctrine in 1855 in the case of Irwin v
Phillips, protecting the sources of water of the
early miners from Johnny-come-latelies. - All appropriative rights granted after 1914
received a permit listing the location of the
diversion, the place of use and the quantity to
be diverted.
36Correlative rights
- These are the groundwater equivalent to riparian
rights. - If there is water below your land, it is yours to
use. - If the groundwater basin is adjudicated, you will
be limited to a specific share of the aquifers
sustainable yield. If not, you can take all you
want. - Lack of adjudication can lead to many conflicts.
37California water rights
- Article X, Section 2 of the California
Constitution applies to all water rights,
prohibits waste of water, and requires
reasonableness of use. - The State Water Resources Control Board grants
permits, and adjudicates water rights and water
rights disputes. - Water rights disputes are common and complex
(Twain - whiskey is for drinkin, water is for
fightin)
38Water regulations
- In most countries, there is usually a complex set
of federal, regional (state) and local
regulations concerning water. - Different legislative branches that have
responsibility for different sectors - the
environment, public health, forestry, transport,
mining, etc. - set policy and draft laws that
affect water resources.
39US regulations - CWA
- Clean Water Act of 1977. Developed out of the
Federal Water Pollution Control Act of 1972, it
prevents pollution of surface water sources from
point pollutants and, more recently, from
non-point pollutants found in stormwater.
40US regulations - SDWA, WSRA
- Safe Drinking Water Act of 1974 prevents the
supply of contaminated drinking water to the
American Public. - Wild Scenic Rivers Act of 1968 maintains the
natural beauty, biology and wildness of American
rivers threatened by the construction of dams,
diversions, canalization, etc.
41US regulations - ESA
- Endangered Species Act of 1973 prevents the
extinction of mostly native animals and plants
through the destruction of important habitat,
particularly aquatic habitat (hence has key role
in water resource management).
42US regulations- NEPA
- National Environmental Policy Act of 1970
mandates requirements for efficient resource use
that avoids general degradation, risk to health
and safety, or other negative consequences of
development, and requires the performance of
Environmental Impact Statements (CA equivalent is
CEQA).
43Regulations at the State level
- In many cases, laws enacted at the federal level
are delegated to the States whos own
authorities, such as the CA State Water Resources
Control Board, are responsible for
implementation, e.g. the Clean Water Act in CA is
enforced through the CA Porter-Cologne Water
Quality Control Act of 1969.
44California water regulations
- In CA, water use and supply are controlled under
a complex system of intermeshing federal and
state laws, common case laws, federal and state
statutes, constitutional amendments, court
rulings and contract agreements that in some way
govern and regulate how water is developed,
allocated or used.
45CA sources of information
- CA has perhaps more water legislation on the
books than any other State. - A complete summary of water laws can be seen in
Volume 1, Chapter 2 of the CA Water Plan (160-94)
with more recent updates tackled in Volume 1,
Chapter 2 of the (160-98) Plan. - Information can also be obtained on the web at
various sites such as http//ceres.ca.gov/topic/e
nv_law/water/ - An excellent book on the subject is California
Water by Littleworth and Garner, 1995.
46Important federal agencies
- The primary federal agencies for water resources
development and protection include Environmental
Protection Agency, US Army Corps of Engineers, US
Bureau of Reclamation, US Geological Survey, US
Department of Agriculture and the US Fish and
Wildlife Service.
47Important CA agencies
- Important CA State agencies for setting or
enforcing water-related regulations include the
CA State Legislature, CA Supreme Court, State
Water Resources Control Board, CA Resources
Agency (esp. CA Dept. of Fish and Game CA Dept.
of Water Resources), and the CA Dept. of Health
Services,
48Important CA govt. agencies
- An interesting and important new player in CA is
the CAL-FED Program. - A state-federal partnership, its role is to
develop a comprehensive solution to provide more
reliable water supplies while stabilizing the
Sacramento-San Joaquin River Delta and SF Bay
ecosystems for fish and wildlife.