BRAE 340 Exam 1
What is the average depth applied (inches) to a 9 acre level basin if the irrigation pump runs at 11 CFS for 4 hours?
1 CFS ≈ 1 ac-in/hr ac-in/hr x hours = ac-in ac-in ÷ acre = inches The correct answer is: 4.89
What salinity (ds/m) is equivalent to a soil moisture tension of 0.34 bars?
1 bar = 100 centibars (cb); 1 dS/m ≈ 30 cb bars x 100 = cb x 1 dS/m/30 cb = dS/m The correct answer is: 1.13 dS/m
A salt concentration of 1324 ppm is equivalent to an electrical conductivity of how many dS/m?
1 dS/m ≈ 700 ppm The correct answer is: 1.89
Statements (1) and (2) refer to water requirements. Are these Net of Gross requirements? (1) The drip system must deliver 48 gallons per tree per day. (2) The sprinklers must apply 36 inches over the course of the irrigation season.
1. Gross 2. Gross
Statements (1) and (2) refer to water requirements. Are these Net of Gross requirements? (1) The sprinklers must apply 36 inches over the course of the irrigation season. (2) The vine requires up to 8 gallons of water per day.
1. Gross 2. Net
In an AVERAGE year, it is estimated that California uses 79.9 MAF of developed water. Identify the percentage (of applied water) used by each of the sectors listed below. Urban Environmental Agricultural
10.5%, 48.5%, 41%
California's urban sector consumes about what portion of its total water supply during an average year?
11%
In a normal year, it is estimated that California consumes 63.5 MAF of water. Identify the percentage (of consumptive use) used by each of the sectors listed below. MISC. & OTHER
15%
California's agriculture consumes about what portion of the total water supply (both undeveloped and developed) during an average year?
16%
California's urban users consume about what percent of its developed water supply in a wet year?
22%
In a normal year, it is estimated that California consumes 63.5 MAF of water. Identify the percentage (of consumptive use) used by each of the sectors listed below. AGRICULTURE
38%
In a normal year, it is estimated that California consumes 63.5 MAF of water. Identify the percentage (of consumptive use) used by each of the sectors listed below. ENVIRONMENTAL
38%
California's agriculture uses about what percent of the developed water supply (water stored in reservoirs and diverted for human purposes) in an average year?
80%
Local, State, and Federal water projects in California transport what approximately what portion of the state's total surface water supply to areas of greatest water demand?
80%
In a normal year, it is estimated that California consumes 63.5 MAF of water. Identify the percentage (of consumptive use) used by each of the sectors listed below. URBAN
9%
Establish in court the priority, amount and/or share of the rights to water from a particular source.
Adjudicate
Allows water to be sold or transferred
Appropriative Rights
Long term storage (more than 30 days) is allowed
Appropriative Rights
Maintenance of right depends on continued use of right
Appropriative Rights
To which water right/doctrine does the following descriptive phrase best apply? Analogous to California gold rush mining law.
Appropriative Rights
To which water right/doctrine does the following descriptive phrase best apply? First in time, first in right.
Appropriative Rights
Water must be used on land adjacent to the water source and within the watershed of that source
Appropriative Rights
Underground rock, gravel or sand which stores and conveys water through pore spaces.
Aquifer
Establishes "reasonable and beneficial" standard for water use.
Article 10, Section 2, Calif. Const.
The water system for a multi-story building is 150 feet tall. How high (ft) must water stand in this system to create a pressure of 1.2 atmospheres (atm) at the base of the system?
Atmospheres * 1 bar/0.987 atm x 14.48 psi/bar x 2.31 ft/psi = ft The correct answer is: 40.7
How do suppressed weirs differ from fully contracted weirs? Select one: A. Contracted weirs are flush with the sides B. Suppressed typically have only a bottom contraction C. There is no difference D. Only one side is contracted E. The presence of an air pocket under the nappe
B
Usually, the most significant beneficial use of water is which of the following? A. Leaching for salt removal B. Crop evapotranspiration (ETc) C. Water use by windbreaks D. Deep percolation E. Reservoir evaporation
B
If the pump delivers 55 acre-ft for an irrigation that is 82% efficient, how much water is beneficial for the crop?
Beneficial => Net = gross x (IE/100) Acre-ft * (IE/100) = Acre-ft gross The correct answer is: 45.10
An irrigation system applies a gross amount of 48 inches of water during the growing season. An evaluation determines that: 29 inches goes to satisfy crop ET; 8 inches runs off and is not collected for reuse; 4.4 inches passes through the root zone as deep percolation (total deep percolation), of which 1 inch is beneficial leaching for salt removal; and 1 inch is ET from weeds. What would the efficiency be if the gross application was reduced because the runoff was elimnated?
Beneficial uses => crop ET + leaching Eliminating ruoff does not change beneficial use. New gross applied is equal to original gross applied - runoff IE = (beneficial use/new gross applied) * 100 The correct answer is: 75.0%
Flow measurement is an important component in agriculture. Which of the following is NOT true? A. There is competition from urban and environmental uses B. Agriculture is the largest consumer of fresh water C. Flow measurement always conserves water D. The fresh water supply is limited E. Flow measurement is necessary in agriculture today
C
Which of the following choices best defines leaching? A. Apply soil amendments such as gypsum to chemically neutralize salt in the soil. B. Applying biomass to increase the soil's organic matter. This blocks the damaging effects of the salt. C. Applying extra water to cause deep percolation which washes salts below the root zone. D. Applying special treatment to cleanse ("leach") the salt from the irrigation water before irrigation. E. Applying extra water which runs off, carrying salt with it.
C
Agencies working together to coordinate SWP and CVP operations to improve Bay-Delta conditions
CALFED
Cooperative group of Federal and State water-related agencies
CALFED
To which of the water institutions listed below does each descriptive phrase best apply? Group of agencies that work together on Bay-Delta issues
CALFED
To which of the water institutions listed below does each descriptive phrase best apply? Group of agencies that work together to set Bay-Delta water quality standards
CALFED
A pump delivers a gross flow rate of 2.7 CFS to a 9 acre field for 9 hours. The irrigation efficiency is 74%. What is the net amount of water benefiting the crop?
CFS x 60 sec/1 min x 60 min/1 hr = cu-ft/hr cu-ft/hr x hours x 1 ac/43560 sq-ft = ac-ft ac-ft / acres x 12 in/ft = inches gross (this is a gross amount because it is coming from the pump) Net = Gross (in) x (IE/100) = inches net The correct answer is: 1.98 inches
Match the flow measurement device to the information that needs to be collected to get a flow rate reading. METER GATE
Change in water level and gate opening
Match the flow measurement device to the information that needs to be collected to get a flow rate reading. SUBMERGED ORIFICE
Change in water level and hole size
Implements decisions regarding water allocations
DWR
Operates State Water Project (SWP)
DWR
To which of the water institutions listed below does each descriptive phrase best apply? Deals with California's water related administrative issues
DWR
To which of the water institutions listed below does each descriptive phrase best apply? Operates the CIMIS program in California, provides ETo estimates
DWR
To which of the water institutions listed below does each descriptive phrase best apply? Responsible for record-keeping on crops, acreages and water use
DWR
Match the flow measurement device to the information that needs to be collected to get a flow rate reading. ITRC WEIR STICK
Depth over the weir crest, including run-up
During which type of water year does California's agriculture sector use more water than the other sectors?
Dry
Federal agency that oversees the Clean Water Act.
EPA
To which of the water institutions listed below does each descriptive phrase best apply? Administers the Federal Safe Drinking Water Act
EPA
To which of the water institutions listed below does each descriptive phrase best apply? Federal agency that oversees the Clean Water Act
EPA
Critical flow can have multiple water depths with the same flow rate.
False
During the drought, water conservation efforts are largely ineffective
False
If individual farmers were 60% efficient in their water use, the proportion of water used in agriculture that can be "saved" and reallocated through water transfers is about 40%.
False
Marketing or transferring water from one district or region to another is controversial, and is not expected to play a significant role in meeting California's future water needs.
False
Subsidence and reduced aquifer storage capacity is less related to groundwater overdraft than to compaction or heavy farm equipment traffic.
False
Subsurface drainage systems are rarely used throughout the San Joaquin, Imperial and Coachella Valleys to drain excess or saline water from the root zone.
False
Water conservation is not likely to have an impact of California's water budget.
False
Water from State water projects is generally less expensive than water from Federal projects.
False
All-American Canal
Federal
CVP
Federal
Claire Engle LAke
Federal
Claire Engle Lake
Federal
Coachella Canal
Federal
Coalinga Canal
Federal
Delta-Mendota Canal
Federal
Folsom Canal
Federal
Folsom Lake
Federal
Friant-Kern Canal
Federal
Madera Canal
Federal
Shasta lake
Federal
Tehama-Colusa Canal
Federal
Applies to Indian & military reservations, National Parks, and Monuments
Federal Reserved Rights
Applies to National Parks and National Forests
Federal Reserved Rights
Establishment of reservation implies right to sufficient water to accomplish intended purpose
Federal Reserved Rights
Grants enough water to accomplish the purposes for which the reservation was established
Federal Reserved Rights
To which water right/doctrine does the following descriptive phrase best apply? Legal concept supported through Supreme Court decisions.
Federal Reserved Rights
Mandated the formation of the State Department of Water Resources.
Governor of CA
A farmer grows 91 acres of a crop that requires 40 inches (net) of irrigation per year. Water costs $71 per acre-ft in this area. What would the annual water cost be if the irrigation efficiency is 80%?
Gross = net (in/yr) ÷ (IE/100) * 1 ft/12 in = ft/yr Volume = depth x area ft/yr * acres = ac-ft/yr Cost = ac-ft/yr * $/ac-ft = $/yr The correct answer is: $26921/yr
f the crop requires an irrigation of 3.0 inches, and the irrigation efficiency is 65%, what amount (inches) must the pump deliver to the irrigation system?
Gross = net ÷ (IE/100) The correct answer is: 4.6
Match the flow measurement device to the information that needs to be collected to get a flow rate reading. RECTANGULAR WEIR
Head upstream above the crest
Match the flow measurement device to the information that needs to be collected to get a flow rate reading. REPLOGLE FLUME
Head upstream above the crest
Match the flow measurement device to the information that needs to be collected to get a flow rate reading. TRAPEZOIDAL WEIR
Head upstream above the crest
Match the flow measurement device to the information that needs to be collected to get a flow rate reading. TRIANGULAR WEIR
Head upstream above the crest
Governed by an elected Board of Directors
Irrigation District
To which of the water institutions listed below does each descriptive phrase best apply? Can receive loans and contract to repay
Irrigation District
To which of the water institutions listed below does each descriptive phrase best apply? Formal association of water users, formation governed by State law
Irrigation District
To which of the water institutions listed below does each descriptive phrase best apply? Governed by an elected Board of Directors
Irrigation District
To which of the water institutions listed below does each descriptive phrase best apply? Has power to levy taxes
Irrigation District
To which of the water institutions listed below does each descriptive phrase best apply? Holds water rights for farmers
Irrigation District
To which of the water institutions listed below does each descriptive phrase best apply? Non-profit entity, but can maintain cash reserve
Irrigation District
An official document giving permission to appropriate water.
License
Colorado River Aqueduct
Local
Hetch-Hetchy Aqueduct
Local
LA Aqueduct
Local
Los Angeles Aqueduct
Local
A metric sprinkler catalog shows a sprinkler that delivers 0.51 liters/sec (Lps) at an operating pressure of 98 feet of head. What is the sprinkler flow rate in gallons per minute (gpm)?
Lps x 15.85 gpm/Lps The correct answer is: 8.1
80 acres of grapes requires 31 inches (net) of irrigation per year. The irrigation efficiency is 65%. How much water could be saved if the irrigation efficiency was increased to 79%?
Original gross = net (in) / (IE/100) * 1 ft/12 in = ft Original volume = depth x area = ft * acres = ac-ft New gross = net (in) / (New IE/100) x 1 ft/12 in = ft New volume = depth x area = ft * acres = ac-ft Savings = new ac-ft - original ac-ft The correct answer is: 56.3 ac-ft
Can be used to force sufficient in-stream flows to meet navigational, fish and wildlife needs
Public Trust Doctrine
Certain resources (water) are the property of all citizens, and are held in trust by the State
Public Trust Doctrine
Legal basis can be traced to laws of the early Roman Empire
Public Trust Doctrine
Prevents ag/urban users from claiming so much water that navigation is excessively harmed
Public Trust Doctrine
Requires sufficient water to remain in streams to support navigation and fish populations
Public Trust Doctrine
The State holds water in trust, and sets allocations and operations to maximize benefits for all citizens
Public Trust Doctrine
To which water right/doctrine does the following descriptive phrase best apply? Balances in-stream needs (navigation, fish habitat, environmental values) with urban and ag needs.
Public Trust Doctrine
To which water right/doctrine does the following descriptive phrase best apply? Legal basis can be traced to laws of the early Roman Empire.
Public Trust Doctrine
To which water right/doctrine does the following descriptive phrase best apply? Requires consumptive uses of water to be balanced against in-stream uses.
Public Trust Doctrine
To which water right/doctrine does the following descriptive phrase best apply? Water cannot be owned by individuals - it is the property of all the citizens of the State.
Public Trust Doctrine
Water cannot be owned by individuals - it is the property of all the citizens of the State
Public Trust Doctrine
Population growth, urban sprawl, and annexation are reasons to increase quantity of this water right
Pueblo Rights
To which water right/doctrine does the following descriptive phrase best apply? Based on Spanish Law.
Pueblo Rights
To which water right/doctrine does the following descriptive phrase best apply? Quantity of right can increase with population or annexation.
Pueblo Rights
Town's water right limited to town needs - excess cannot be sold to others
Pueblo Rights
Continuous flow measurement means flow rates are:
Recorded automatically on site at set time intervals
Based on English Common Law
Riparian Rights
State acts as trustee of water for the citizens, who are acutal owners of the State's water
Riparian Rights
To which water right/doctrine does the following descriptive phrase best apply? Water cannot be stored, sold or tansferred.
Riparian Rights
Was enacted in November 2009, requiring all water suppliers to increase water use efficiency
SBx7
To which of the water institutions listed below does each descriptive phrase best apply? Adopted water quality standards for Delta in May 1995
SWRCB
California Aqueduct
State
Edmonston Pumping Plant
State
Lake Oroville
State
North Bay Aqueduct
State
SWP
State
Lower in priority than superior rights. Can only be satisfied with water leftover after superior rights.
Subordinate Right
Higher in priority than subordinate rights. Must be satisfied before allocating to subordinate rights.
Superior Right
An alfalfa crop uses 0.38 inches per day. How many days will it take to extract 4.42 inches from the soil?
Time = amount (in)/ rate (in/day) = days The correct answer is: 11.6
Best Management Practices (BMP's) are urban water conservation practices, and include the use of water-saving plumbing fixtures.
True
Eliminating ground water overdraft doesn't require that all pumping from the ground water stop.
True
Increased population means increased demand for water for industrial use.
True
Municipalties currently have great interest in building additional water storage resevoirs for urban supply.
True
Reclaimed water is not likely to be a significant source of drinking water in the near future.
True
The cost of reclaimed water has been and is a deterrent to using this water for agriculture.
True
Water quality issues particularly important in the Delta include salinity and minimum flows.
True
Federal builder of flood control projects, which are often used for irrigation as well
US Army Corps of Engineers
Federal developer of dams, canals and irrigation projects
USBR
To which of the water institutions listed below does each descriptive phrase best apply? Builder of projects with partial repayment obligations for water users
USBR
To which of the water institutions listed below does each descriptive phrase best apply? Established by the Reclamation Act of 1902
USBR
To which of the water institutions listed below does each descriptive phrase best apply? Formed in 1902 as a branch of the Department of the Interior
USBR
To which of the water institutions listed below does each descriptive phrase best apply? Subsidized Federal water projects to promote development of the West
USBR
Match the flow measurement device to the information that needs to be collected to get a flow rate reading. PARSHALL FLUME
Upstream water level
Reasons for decreased irrigated area in California include crop subsidies and export markets.
Urbanization, salinization and high water costs are reasons for decreased irrigated acreage. The correct answer is 'False'.
A right to use the water, but not to own the fluid itself
Usufructuary Right
A rain gauge is constructed of a funnel with diameter D = 4 inches, fixed to the top of a tube with diameter d = 1 inches (see drawing). Rain water stands 3.38 inches high in the bottom of the tube. How much rainfall does that indicate?
Volume in tube = column x tube area Tube area = ∏ d2/4 = sq-in Volume in tube = rainfall (in) x tube area = cu-in Rain depth = volume in tube (cu-in) ÷ top funnel area (sq-in) The correct answer is: 0.21 inches
Area determined by topography contributing to a particular surface water source (stream, lake, etc.).
Watershed
Water agencies' agreement to move water between them (direct conveyance system need not exist).
Wheeling
Also known as the Irrigation District Law, allowed formation of local irrigation districts.
Wright Act, 1887
How many gallons of water does it take to produce a 97 pound bale of alfalfa if a 115 acre center pivot requires 72 inches of water and produces 11.8 tons per acre?
Your answer is correct. 1 acre * in = ac-in You only need one acre because the tons of product is per acre. ac-in * 1 AF/12 ac-in = AF AF * 325830 gal/AF = Gal Gal ÷ tons = Gal/ton Gal/ton * 1 ton/2000lbs * lbs/bale = gal/bale The correct answer is: 8035 gallons/bale
What concentration (ppm) is equivalent to a soil moisture tension of 1.5 bars?
bars x 100 = cb cb x 1dS/m/30 cb = dS/m dS/m x 700 ppm/1 dS/m = ppm The correct answer is: 3500
456775 gallons of water are added to a reservoir (with straight sides) covering 3.4 acres. How many inches does the water level rise after the water is added?
gallons ÷ 7.48 gal/cu-ft = cu-ft cu-ft ÷ acres ÷ 43560 sq-ft/acre = ft ft x 12 in/ft = inches The correct answer is: 4.9
A grass area uses about 1.7 inches per week. How many gallons of water per day does 1.1 acres of turf grass use?
in/week x 1 week/7 days = in/day in/day x acres x 1 ft/12 in = ac-ft/day ac-ft/day x 43560 sq-ft/acre x 7.48 gal/cu-ft = gal/day The correct answer is: 7253.6
A grass area uses about 3.2 inches per week. How many acre-feet of water per day does 28460 square feet of turf grass use?
in/week x 1 week/7 days x 1 ft/12 inches = ft/day ft/day x sq-ft = cu-ft/day cu-ft/day x 1 acre/43560 sq-ft = ac-ft/day The correct answer is: 0.025
If a soil has a moisture tension of 0.17 bars and the salinity of the soil water is 1.48 dS/m, what is the total tension experienced by the plant roots? That is, what is the sum of the moisture tension and the osmotic (due to salinity) tension?
moisture tension = bars x 100 cb/bar = cb osmotic tension = dS/m x 30 cb/(1 dS/m) = cb total tension = moisture tension (cb) + osmotic tension (cb) The correct answer is: 61 cb
An elevated water tank is used to feed water into a drip system. How high (ft) must the tank outlet be in order to cause a 31 psi pressure at the inlet of the drip system?
psi x 2.31 ft/psi = ft The correct answer is: 71.6
What pumping rate (CFS) is required to deliver 63 acre-inches in 20 hours?
rate = amount ÷ time rate = ac-in/hr x 1 CFS/1 ac-in/hr = CFS The correct answer is: 3.15
