TEXAS IRRIGATION COMPRHENSIVE EXAM 2025/2026
QUESTIONS AND ANSWERS RATED A+
✔✔An approved ---- is the unobstructed vertical distance through free atmosphere
between the lowest pint of water supply outlet and the flood level rim of the fixture or
assembly into which the outlet discharges. There vertical, physical separations must be
at least twice the diameter of the water supply outlet, but never less than 1 in. - ✔✔Air
Gap
✔✔Small device used on some subsurface drop irrigation that allows air into the
dripperline when the system is not running which eliminates any vacuum that could
result in debris or contaminants being sucked into the piping system - ✔✔Air/Vacuum
Relief Valve
✔✔The amount of water, in irrigation management, that is allowed to be depleted from
the plant available water before an irrigation event is scheduled. Also referred to as
Managed Allowable Depletion (MAD). Generally, 50% depletion is the rule of thumb -
✔✔Allowable Depletion (AD)
✔✔An electric current that reverses it direction periodically - ✔✔Alternating Current
(AC)
✔✔Any device that introduces air into the system to prevent "back siphonage." -
✔✔Anti-Siphon Device
✔✔Rate at which water is applied by sprinkler heads in a certain pattern. Usually
measured in inches per hour, gallons per hour or gallons per day. Commonly called
"precipitation rate". - ✔✔Application rate
✔✔What are the three methods in which to evaluate application rates? - ✔✔1. a
densogram
2. Precipitation rate formula
96.3 x total GPM / total area
3. a water audit
✔✔An underground layer or porous rock, sand, etc. containing water, into which wells
can be sunk - ✔✔Aquifer
✔✔The surface area of the landscape to which a sprinkler head will provide water.
Usually described in degrees or part of a full circle head. The degrees of coverage of a
sprinkler from one side of a pattern to the other. - ✔✔Arc
✔✔Scale expressing foot measurements in parts of an inch - ✔✔Architect Scale
,✔✔A corrected or redrawn plan showing the "actual scaled" location of all major
components of the system and other information the property owner might require. An --
-- is an individual tool form irrigators to locate major components at a later date - ✔✔As-
Built Plan
✔✔A back flow prevention device that allows air into the piping system, with the use of
a float that moves up and down, to prevent backsiphonage. No back pressure can exist
for proper operation. It cannot be under constant pressure for more than 12 hours in any
24- hour period. This device must be installed vertically and a minimum of 6' higher than
all down stream piping and the highest downstream head or outlet. There cannot be any
shut off valves downstream of the ---. A separate --- must be installed on the discharge
side of each control valve, between the valve and all emission devices. -
✔✔Atmospheric Vacuum Breaker (AVB)
✔✔An electrical or hydraulic control valve in a sprinkler system which is activated by an
automatic controller. Also called a section valve, circuit valve, zone valve, remote
control valve, electrical valve, or hydraulic valve - ✔✔Automatic Control Valve
✔✔An irrigation system which will automatically cycle (water) according to a preset
program - ✔✔Automatic System
✔✔Water (measured in inch of water per inch of soil) that is actually accessible for the
plant to use - ✔✔Available Water
✔✔What does AWWA stand for? - ✔✔American Water Works Association
✔✔An unwanted reversal of the flow of water in a piping system which can potentially
allow non-potable water to pollute or contaminate the potable water supply. Caused by
back pressure or backsiphonage - ✔✔Backflow
✔✔Any condition that could create pressure in the discharge (outlet or downstream)
side of the piping system that is greater than that of the supply (inlet or upstream) side
of the system. Examples of this occurrence would be pressure caused by gravity (due to
elevation), a pump installed on the system or steam and/or air pressure -
✔✔Backpressure
✔✔A form of back flow due to negative or sub-atmospheric pressure within the water
system. A break in the city main line or a fire department utilizing excessive water to
fight a nearby fire could both induce a ---- - ✔✔Backsiphonage
✔✔Any approved device which prevents an undesirable reversal of flow of water by the
introduction of air, use of check valves, or a combination of both principles. -
✔✔Backflow Prevention Methods
,✔✔What are some examples of back flow prevention methods? - ✔✔1. an air gap
2. an atmospheric vacuum breaker (AVB)
3. a pressure vacuum breaker (PVB)
4. spill-resistant pressure vacuum breaker (SRPVB)
5. a double check valve assembly (DCVA)
6. a reduced pressure principle assembly (RPPA)
✔✔Type of rotary sprinkler in which rotation is achieved by a steel ball which is set into
a circular motion by water passing through the head - ✔✔Ball Driven Head
✔✔A section of sprinklers controlled by one zone valve - ✔✔Block (of heads)
✔✔The exterior case or shell of the sprinkler - ✔✔Body (of heads)
✔✔A pump which is installed in the water supply line and is designed to raise the
pressure in the irrigation system - ✔✔Booster Pump
✔✔A type of sprinkler head designed to irrigate level and defined shrub beds. It is
mounted on a riser and puts out a very small umbrella-shaped adjustable flow of water -
✔✔Bubblers
✔✔The pipe fitting used to change an irrigation component to a larger or smaller size -
✔✔Bushing
✔✔The main effect distributing water horizontally through the soil - ✔✔Capillary Action
✔✔Containers that are used to collect measurable water in order to conduct a water
audit - ✔✔Catchment Devices
✔✔Rating of the smoothness of the inside of pipe. The higher the ----, the smoother the
inside diameter of the pipe. PVC has a ---- of 150, whereas copper is 140. Generally,
the ---- decreases over time indicating the pipe gets rougher, resulting in increased
friction loss - ✔✔C-Factor
✔✔A valve which permits water to flow in one direction only - ✔✔Check Valve
✔✔These devices are usually located within the sprinkler head for the purpose of
preventing water in the piping to drain out of the sprinkler heads when the system is
shut off. Therefore, this type of anti-drain check valve becomes an individual tool for
managing water when dealing with sloped landscapes - ✔✔Check valve for "low head
drainage"
, ✔✔A method by which PVC pipe is grouped according to the working pressure.
Pressure rated with a wall thickness in direct ratio to the diameter. All sizes in that class
have the same working pressure - ✔✔Class Pipe
✔✔A line of equal elevation drawn on a plan. For example, a --- labeled "250" means
that everywhere along that line is 250 feet above mean sea level. ---- are usually
accurate to +/- one-half of the contour interval; ie. when a contour interval of one-foot is
indicated on a plan, a particular ---- will be accurate to +/- 6 inches - ✔✔Contour line
✔✔The wires (from the automatic controller) which transit signals to the automatic
electrical valves to open and close - ✔✔Control Wires
✔✔An automatic timing device, which signals the automatic valves to open or close
according to the prescribed program. Because of current technological advances, ---
have expanded from very simple mechanical devices to very sophisticated central
control units that operate numerous satellite units in the field. Wireless automatic
systems are emerging and PC irrigation --- interface hardware and software solutions
are becoming the standard for city parks, golf, and commercial sites. - ✔✔Controller
✔✔A bronze tube with a handle which inserts into a quick coupler valve (and turned one
quarter revolution) for supplemental water. May be fitted with a sprinkler head, hose
swivel or faucet - ✔✔Coupler Key
✔✔The pattern of water that a certain sprinkler covers. Various sprinklers or sprinkler
nozzles have varying patterns of coverage: quarter, half, full, etc. Most manufactures
even have adjustable arc nozzles that suffice for many odd-shaped areas -
✔✔Coverage
✔✔Any actual or potential connection between a potable water supply and any source
of contamination or pollution - ✔✔Cross Connection
✔✔Refers to one complete operation of the controller through a watering program -
✔✔Cycle
✔✔Coefficient used to adjust the potential (or reference) evapotranspiration to reflect
the usage of water in relation to the density of the planting - ✔✔Density Factor
✔✔Graphic representation of precipitation. Higher rates are indicated by darker colors.
There are given to check the amount of precipitation and uniformity in a given irrigation
area - ✔✔Densogram
✔✔The sum total of the desired (or minimum) head pressure added to the total of all
pressure losses. A stated pressure indicating the minimum pressure required for the
QUESTIONS AND ANSWERS RATED A+
✔✔An approved ---- is the unobstructed vertical distance through free atmosphere
between the lowest pint of water supply outlet and the flood level rim of the fixture or
assembly into which the outlet discharges. There vertical, physical separations must be
at least twice the diameter of the water supply outlet, but never less than 1 in. - ✔✔Air
Gap
✔✔Small device used on some subsurface drop irrigation that allows air into the
dripperline when the system is not running which eliminates any vacuum that could
result in debris or contaminants being sucked into the piping system - ✔✔Air/Vacuum
Relief Valve
✔✔The amount of water, in irrigation management, that is allowed to be depleted from
the plant available water before an irrigation event is scheduled. Also referred to as
Managed Allowable Depletion (MAD). Generally, 50% depletion is the rule of thumb -
✔✔Allowable Depletion (AD)
✔✔An electric current that reverses it direction periodically - ✔✔Alternating Current
(AC)
✔✔Any device that introduces air into the system to prevent "back siphonage." -
✔✔Anti-Siphon Device
✔✔Rate at which water is applied by sprinkler heads in a certain pattern. Usually
measured in inches per hour, gallons per hour or gallons per day. Commonly called
"precipitation rate". - ✔✔Application rate
✔✔What are the three methods in which to evaluate application rates? - ✔✔1. a
densogram
2. Precipitation rate formula
96.3 x total GPM / total area
3. a water audit
✔✔An underground layer or porous rock, sand, etc. containing water, into which wells
can be sunk - ✔✔Aquifer
✔✔The surface area of the landscape to which a sprinkler head will provide water.
Usually described in degrees or part of a full circle head. The degrees of coverage of a
sprinkler from one side of a pattern to the other. - ✔✔Arc
✔✔Scale expressing foot measurements in parts of an inch - ✔✔Architect Scale
,✔✔A corrected or redrawn plan showing the "actual scaled" location of all major
components of the system and other information the property owner might require. An --
-- is an individual tool form irrigators to locate major components at a later date - ✔✔As-
Built Plan
✔✔A back flow prevention device that allows air into the piping system, with the use of
a float that moves up and down, to prevent backsiphonage. No back pressure can exist
for proper operation. It cannot be under constant pressure for more than 12 hours in any
24- hour period. This device must be installed vertically and a minimum of 6' higher than
all down stream piping and the highest downstream head or outlet. There cannot be any
shut off valves downstream of the ---. A separate --- must be installed on the discharge
side of each control valve, between the valve and all emission devices. -
✔✔Atmospheric Vacuum Breaker (AVB)
✔✔An electrical or hydraulic control valve in a sprinkler system which is activated by an
automatic controller. Also called a section valve, circuit valve, zone valve, remote
control valve, electrical valve, or hydraulic valve - ✔✔Automatic Control Valve
✔✔An irrigation system which will automatically cycle (water) according to a preset
program - ✔✔Automatic System
✔✔Water (measured in inch of water per inch of soil) that is actually accessible for the
plant to use - ✔✔Available Water
✔✔What does AWWA stand for? - ✔✔American Water Works Association
✔✔An unwanted reversal of the flow of water in a piping system which can potentially
allow non-potable water to pollute or contaminate the potable water supply. Caused by
back pressure or backsiphonage - ✔✔Backflow
✔✔Any condition that could create pressure in the discharge (outlet or downstream)
side of the piping system that is greater than that of the supply (inlet or upstream) side
of the system. Examples of this occurrence would be pressure caused by gravity (due to
elevation), a pump installed on the system or steam and/or air pressure -
✔✔Backpressure
✔✔A form of back flow due to negative or sub-atmospheric pressure within the water
system. A break in the city main line or a fire department utilizing excessive water to
fight a nearby fire could both induce a ---- - ✔✔Backsiphonage
✔✔Any approved device which prevents an undesirable reversal of flow of water by the
introduction of air, use of check valves, or a combination of both principles. -
✔✔Backflow Prevention Methods
,✔✔What are some examples of back flow prevention methods? - ✔✔1. an air gap
2. an atmospheric vacuum breaker (AVB)
3. a pressure vacuum breaker (PVB)
4. spill-resistant pressure vacuum breaker (SRPVB)
5. a double check valve assembly (DCVA)
6. a reduced pressure principle assembly (RPPA)
✔✔Type of rotary sprinkler in which rotation is achieved by a steel ball which is set into
a circular motion by water passing through the head - ✔✔Ball Driven Head
✔✔A section of sprinklers controlled by one zone valve - ✔✔Block (of heads)
✔✔The exterior case or shell of the sprinkler - ✔✔Body (of heads)
✔✔A pump which is installed in the water supply line and is designed to raise the
pressure in the irrigation system - ✔✔Booster Pump
✔✔A type of sprinkler head designed to irrigate level and defined shrub beds. It is
mounted on a riser and puts out a very small umbrella-shaped adjustable flow of water -
✔✔Bubblers
✔✔The pipe fitting used to change an irrigation component to a larger or smaller size -
✔✔Bushing
✔✔The main effect distributing water horizontally through the soil - ✔✔Capillary Action
✔✔Containers that are used to collect measurable water in order to conduct a water
audit - ✔✔Catchment Devices
✔✔Rating of the smoothness of the inside of pipe. The higher the ----, the smoother the
inside diameter of the pipe. PVC has a ---- of 150, whereas copper is 140. Generally,
the ---- decreases over time indicating the pipe gets rougher, resulting in increased
friction loss - ✔✔C-Factor
✔✔A valve which permits water to flow in one direction only - ✔✔Check Valve
✔✔These devices are usually located within the sprinkler head for the purpose of
preventing water in the piping to drain out of the sprinkler heads when the system is
shut off. Therefore, this type of anti-drain check valve becomes an individual tool for
managing water when dealing with sloped landscapes - ✔✔Check valve for "low head
drainage"
, ✔✔A method by which PVC pipe is grouped according to the working pressure.
Pressure rated with a wall thickness in direct ratio to the diameter. All sizes in that class
have the same working pressure - ✔✔Class Pipe
✔✔A line of equal elevation drawn on a plan. For example, a --- labeled "250" means
that everywhere along that line is 250 feet above mean sea level. ---- are usually
accurate to +/- one-half of the contour interval; ie. when a contour interval of one-foot is
indicated on a plan, a particular ---- will be accurate to +/- 6 inches - ✔✔Contour line
✔✔The wires (from the automatic controller) which transit signals to the automatic
electrical valves to open and close - ✔✔Control Wires
✔✔An automatic timing device, which signals the automatic valves to open or close
according to the prescribed program. Because of current technological advances, ---
have expanded from very simple mechanical devices to very sophisticated central
control units that operate numerous satellite units in the field. Wireless automatic
systems are emerging and PC irrigation --- interface hardware and software solutions
are becoming the standard for city parks, golf, and commercial sites. - ✔✔Controller
✔✔A bronze tube with a handle which inserts into a quick coupler valve (and turned one
quarter revolution) for supplemental water. May be fitted with a sprinkler head, hose
swivel or faucet - ✔✔Coupler Key
✔✔The pattern of water that a certain sprinkler covers. Various sprinklers or sprinkler
nozzles have varying patterns of coverage: quarter, half, full, etc. Most manufactures
even have adjustable arc nozzles that suffice for many odd-shaped areas -
✔✔Coverage
✔✔Any actual or potential connection between a potable water supply and any source
of contamination or pollution - ✔✔Cross Connection
✔✔Refers to one complete operation of the controller through a watering program -
✔✔Cycle
✔✔Coefficient used to adjust the potential (or reference) evapotranspiration to reflect
the usage of water in relation to the density of the planting - ✔✔Density Factor
✔✔Graphic representation of precipitation. Higher rates are indicated by darker colors.
There are given to check the amount of precipitation and uniformity in a given irrigation
area - ✔✔Densogram
✔✔The sum total of the desired (or minimum) head pressure added to the total of all
pressure losses. A stated pressure indicating the minimum pressure required for the
