CSLB Landscaping (C-27) Trade — All Questions

A site is exposed to steady afternoon wind. How should the designer adjust spray head spacing?

• a.Reduce spacing below the normal head-to-head distance✓
• b.Increase spacing and raise operating pressure to push through the wind
• c.Increase spacing and change to a finer nozzle pattern
• d.Keep spacing the same and add a second controller program

Wind shortens and distorts the pattern, so tightening spacing below the usual head-to-head distance is how the design keeps coverage uniform. Raising pressure produces finer droplets that blow away more readily. A second program changes timing, not coverage. Finer nozzles at wider spacing make drift worse rather than better.

A zone contains quarter-circle, half-circle, and full-circle spray heads on the same laterals. What must be true of the nozzles for the zone to water evenly?

• a.Every head must carry a nozzle of the same flow rate
• b.Quarter-circle heads must be placed on their own lateral
• c.Full-circle heads must run at a higher operating pressure
• d.Nozzle flow must scale with arc to match precipitation✓

A full circle covers four times the area of a quarter, so its nozzle must pass roughly four times the flow for the two to apply water at the same depth per hour, which is what matched precipitation rate nozzle sets provide. Equal flow at unequal arcs floods the quarters. Changing pressure by head is not practical. Splitting arcs onto separate laterals does not fix the nozzle mismatch.

A remodel connects several spray heads and two rotors to the same control valve. What is the consequence?

• a.The spray heads will mist because the rotors restrict flow
• b.One group is overwatered while the other stays dry✓
• c.The valve will fail to open because of mixed flow demand
• d.The rotors will lose pressure and stop rotating entirely

Rotors apply water far more slowly than sprays, so a run time that satisfies the rotors drowns the spray area and a run time that suits the sprays leaves the rotor area dry. The valve opens normally on mixed flow. Rotors may still turn, and the misting seen at spray heads comes from excess pressure rather than from sharing a valve.

A plan groups plants onto valves by water need, sun exposure, and root depth. What is this design practice called?

• a.Hydrozoning the landscape✓
• b.Establishing the irrigation audit baseline
• c.Calculating the landscape coefficient
• d.Setting the distribution uniformity target

Grouping plants with similar water demand and exposure onto a common valve is hydrozoning, and it is the core requirement that lets a schedule serve every plant on a station. An audit baseline is a measurement of an installed system. Distribution uniformity describes how evenly a zone applies water. The landscape coefficient is a number used in a water budget calculation.CA MWELO (Title 23)

Water begins running off a clay slope about eight minutes into a 20-minute rotor cycle. What is the correct schedule change?

• a.Keep the 20 minutes and add a wetting agent to the soil
• b.Cut the cycle to eight minutes and water every other day
• c.Water for 40 minutes once a week to drive moisture deeper
• d.Run three cycles of about seven minutes with soak between✓

Runoff starts when the application rate passes the soil intake rate, so splitting the total into short cycles separated by soak periods lets the same depth of water enter without leaving the slope. Simply shortening the cycle underwaters the root zone. A wetting agent does not raise clay intake enough to matter. Doubling the run time multiplies the runoff.

Four soils are being compared for irrigation scheduling. Which has the lowest infiltration rate and therefore the highest runoff risk?

• a.A gravelly loam over decomposed granite
• b.A coarse sand with little organic matter
• c.A compacted silty clay on a graded pad✓
• d.A sandy loam amended with compost

Fine particles and compaction together produce the smallest pore spaces, so a compacted silty clay takes water in most slowly and sheds the rest. Coarse sand accepts water fastest. An amended sandy loam has good structure and intake. A gravelly loam over decomposed granite drains readily and rarely generates runoff.

A California schedule is built around a reference evapotranspiration value pulled from a CIMIS station. What does that value describe?

• a.The depth of water a drip zone applied per hour
• b.The depth of water a specific landscape lost last week
• c.The water use of a standard reference crop under the local weather✓
• d.The share of applied water that reached the root zone

Reference evapotranspiration is the water use of a standardized, well-watered reference surface under measured local weather, and it becomes site specific only after a plant factor is applied. It is not a measurement of one landscape, not an application rate, and not a measure of how efficiently water reaches roots, which is what distribution uniformity and efficiency describe.

On a MWELO project, what is the relationship the designer must demonstrate between estimated total water use and maximum applied water allowance?

• a.The two are calculated for separate hydrozones and not compared
• b.Estimated use must not exceed the allowance✓
• c.Estimated use must equal the allowance exactly
• d.The allowance must not exceed estimated use

The allowance is a ceiling set from local reference evapotranspiration and landscape area, and the design passes when estimated total water use lands at or below it. Requiring an exact match would make almost every efficient design fail. Reversing the inequality would force overdesign. The two figures are calculated for the whole landscape precisely so they can be compared.CA MWELO (Title 23)

Under MWELO, a landscape water budget is smaller on a site with which characteristic?

• a.A larger area of special landscape area such as a play field
• b.A drip system rather than an overhead spray system
• c.A lower local reference evapotranspiration value✓
• d.A higher proportion of trees to shrubs in the plan

The allowance is driven by local reference evapotranspiration and landscape area, so a cooler, lower-demand climate zone yields a smaller budget. Special landscape areas are given a higher allowance and raise the budget. The mix of trees and shrubs and the choice of irrigation method affect estimated use and efficiency but are not what sets the allowance itself.CA MWELO (Title 23)

A MWELO project includes a three-foot-wide planter strip between a sidewalk and a curb. What does the ordinance say about irrigating it?

• a.Overhead spray is prohibited and subsurface or drip should be used✓
• b.It may use spray heads if they are pressure regulated
• c.Overhead spray is allowed because the strip is under 500 square feet
• d.It may use spray heads if run only between 8 pm and 10 am

Section 493.2.2(d)(6) requires that areas less than 10 feet in width in any direction be irrigated with subsurface irrigation or other means producing no water waste, runoff, or overspray, so a three-foot strip must use drip or subsurface. Section 493.2.2(d)(10) independently bars overhead irrigation within 24 inches of any non-permeable surface, and a 36-inch strip bounded by sidewalk and curb leaves no compliant location for a spray head. Pressure regulation and night watering reduce waste but do not lift either restriction, and square footage is not the test.23 CCR §493.2.2(d)(6)

Which controller feature does MWELO require on a new automatic irrigation system?

• a.A separate transformer for each group of six stations
• b.Weather-based or soil moisture control with a rain shutoff✓
• c.A mechanical timer with at least four independent programs
• d.A remote shutoff accessible from the public right of way

MWELO requires controllers that adjust to actual conditions, meaning weather-based or soil moisture-based control together with a sensor that suspends watering during rain. Program count on a mechanical timer is not the requirement. A public remote shutoff is not called for. Transformer arrangement is an electrical detail with no bearing on the ordinance.CA MWELO (Title 23)

A master valve and a flow sensor are wired to a smart controller on a large commercial landscape. What is the main benefit of the pair?

• a.Each station can be assigned a separate precipitation rate value
• b.Pressure at the far end of the mainline is held constant
• c.A broken mainline can be detected and shut down automatically✓
• d.Backflow protection is provided without a separate assembly

The sensor watches flow while the master valve can close the mainline, so unexpected flow such as a broken pipe triggers an automatic shutdown instead of a week of running water. Precipitation rates come from nozzles and spacing. Neither device regulates pressure. Neither is an approved backflow assembly, so a separate assembly is still required.

A technician measures 3 ohms across a solenoid on a station that blows the controller fuse. What does that reading indicate?

• a.A weak transformer on the controller side
• b.An open circuit in the field wiring
• c.A shorted solenoid that must be replaced✓
• d.Normal resistance for a 24-volt solenoid

Irrigation solenoids normally read roughly 20 to 60 ohms, so a reading of 3 ohms means the coil has shorted and is drawing enough current to blow the fuse. An open circuit reads as infinite resistance, not near zero. The reading is far below the normal band. A weak transformer lowers voltage but does not change coil resistance.

One station on a 12-station controller will not energize, while every other station runs. Where should troubleshooting begin?

• a.At that station wire and its solenoid, which serve only that zone✓
• b.At the controller transformer, which feeds every station on the unit
• c.At the common wire, which is shared by every station
• d.At the master valve, which opens for every station

A fault that affects one station and no other has to lie in the parts unique to that station, namely its field wire, its splice, and its solenoid. The transformer, the common wire, and the master valve are all shared, so a failure in any of them would take down every station rather than one.

A control valve keeps running after the controller shuts the station off. What is the most likely cause?

• a.Grit lodged under the diaphragm holding the valve open✓
• b.An undersized lateral downstream of the valve
• c.A failed rain sensor holding the station open
• d.A reversed common wire at the controller terminal

A diaphragm valve closes when pressure rebuilds above the diaphragm, and grit that blocks the seat or the port keeps it from seating, so the zone keeps flowing. A rain sensor interrupts the circuit and stops watering rather than continuing it. Common wires are not polarity sensitive on a 24-volt circuit. Lateral size affects pressure, not valve closure.

A C-27 needs 120-volt power at a new controller location on the side of a house. What is the correct approach?

• a.Run the branch circuit in conduit and have it inspected later
• b.Have a licensed electrical contractor install the branch circuit✓
• c.Splice into the nearest exterior light circuit inside a valve box
• d.Install the circuit because the controller is landscape equipment

Low-voltage valve wiring is part of the irrigation system, but installing a new 120-volt branch circuit is electrical work that belongs to an electrical classification, so it must go to a licensed electrical contractor. Adding conduit or an after-the-fact inspection does not change who may perform it. Splicing line voltage in a valve box is both unlicensed work and a serious hazard.

Field splices on 24-volt valve wire are being made at a remote valve manifold. What is required for a durable installation?

• a.Crimped butt connectors sleeved in irrigation tubing
• b.Soldered joints wrapped in electrical tape below the mainline
• c.Waterproof splice connectors made up inside a valve box✓
• d.Twisted wire nuts taped over and buried in the trench

Direct burial wire splices corrode unless they are sealed, so waterproof connectors placed in an accessible valve box are the standard. Taped wire nuts buried in soil fail within a few seasons. Tape over solder is not waterproof and burying the splice under the mainline makes it unreachable. Crimps in tubing are not sealed against moisture.

What is the purpose of the isolation ball valve installed just upstream of a valve manifold?

• a.To regulate downstream pressure on the zones it feeds
• b.To close the manifold for service without draining the main✓
• c.To meter the flow through the manifold for the system flow sensor
• d.To relieve surge pressure when a station closes

An isolation valve lets a technician close off one manifold and repair a control valve while the rest of the mainline stays charged. It is a full-port shutoff, not a regulator, and it does not relieve surge, which is handled by design velocity and slow-closing valves. Metering is a flow sensor function, not a shutoff function.

A quick coupler valve is installed in a large planting bed. What is its normal use?

• a.To break vacuum in a subsurface drip lateral
• b.To provide a temporary hose connection for hand use✓
• c.To drain the mainline for repairs at the low point
• d.To provide a manual override for the nearest station

A quick coupler is opened with a removable key so a hose can be attached wherever hand watering or washdown is needed, then closed and left flush with grade. Draining is done at a drain valve, vacuum relief at an air relief valve, and manual station override at the control valve bleed screw or the controller.

Spray heads on a new zone produce a fine fog rather than droplets. What is the correct correction?

• a.Move to a larger nozzle so more water leaves each head
• b.Reduce the run time so less water is applied per cycle
• c.Add pressure regulation so heads run near rated pressure✓
• d.Add a second valve so fewer heads run at once

Fogging means the heads are operating well above their rated pressure, and pressure regulation at the head or on the zone brings them back into range. Shorter run times leave the same fog and the same drift. A larger nozzle at excessive pressure still atomizes. Fewer heads per valve raises pressure further and makes the problem worse.

A trench crosses a future paver driveway. What should be installed before the paving crew arrives?

• a.A pull box centered under the driveway for wire access
• b.A sleeve about twice the diameter of the carrier pipe✓
• c.A cast iron pipe carrying the mainline under the drive
• d.A concrete thrust block at each side of the driveway

A sleeve about twice the diameter of the carrier pipe lets the mainline and wire be pulled or replaced later without disturbing pavement, which is why sleeving is scheduled before paving. Cast iron is not used for irrigation laterals. Thrust blocks belong at direction changes on large pressure mains. A pull box under a driveway cannot be reached.

Why is an irrigation mainline normally buried deeper than the laterals it feeds?

• a.It carries a larger volume and needs more soil for support
• b.It must be below the frost line in every California climate zone
• c.It stays under constant pressure and is more exposed to damage✓
• d.It must clear the drain lines that cross the same trench

A mainline holds pressure at all times, so a shovel or aerator strike causes an immediate and continuous leak, and extra cover is cheap protection. Volume does not dictate depth. Drain line crossings are handled case by case. Frost depth is not the governing concern across California, where most systems are buried for damage protection rather than freezing.

During a catch-can audit, the driest cups collect about half as much water as the average cup. What does that tell the auditor?

• a.The zone precipitation rate is above the intake rate of the soil profile
• b.The nozzles are operating below their rated pressure
• c.The controller run time is set too short for the zone
• d.Distribution uniformity is poor and dry spots will drive overwatering✓

Wide variation between cups is a distribution uniformity problem, and the usual response in the field is to run the whole zone longer to green up the dry spots, which floods everywhere else. Run time affects total depth but not evenness. Intake rate is measured by watching for runoff. Low pressure is one possible cause but is not what the cup spread by itself demonstrates.

An audit finds mismatched nozzle brands and several worn nozzles on the same turf zone. What is the direct consequence?

• a.A rise in the maximum applied water allowance for the site
• b.A drop in static pressure measured at the point of connection
• c.Increased low-head drainage at the end of each cycle
• d.Uneven precipitation across the zone and reduced uniformity✓

Nozzles from different families throw different patterns and rates, and worn nozzles spray more water at a shorter radius, so the zone applies water unevenly. Static pressure at the meter is unaffected by nozzle wear. The water allowance is a calculated ceiling, not something nozzles change. Low-head drainage depends on head elevation and check valves.

A zone applies water at 1.6 inches per hour and the schedule calls for 0.4 inches. What run time delivers that depth?

• a.10 minutes
• b.40 minutes
• c.24 minutes
• d.15 minutes✓

Dividing the required depth by the precipitation rate gives 0.4 divided by 1.6, or 0.25 hours, which is 15 minutes. Ten minutes applies about 0.27 inches. Twenty-four minutes applies about 0.64 inches. Forty minutes applies more than an inch, which on most soils would run off long before the cycle ended.

A zone of eight heads at 2.5 GPM each covers 1,200 square feet. What is its precipitation rate?

• a.About 0.8 inches per hour
• b.About 1.6 inches per hour✓
• c.About 1.2 inches per hour
• d.About 2.4 inches per hour

Total flow is 20 GPM, and 96.3 times 20 divided by 1,200 gives about 1.6 inches per hour. The 0.8 figure would come from half the flow or twice the area. The 1.2 figure does not follow from either input. The 2.4 figure would require roughly 30 GPM over the same area.

Rotary nozzles are substituted for standard spray nozzles on a sloped turf area. What schedule change follows?

• a.Shorter run times, because rotary nozzles apply water faster
• b.Longer run times, because rotary nozzles apply water more slowly✓
• c.Shorter run times, because the streams resist wind drift
• d.The same run times, because the nozzles thread onto the same bodies

Rotary nozzles put out a much lower precipitation rate than fixed sprays, so the same depth of water takes noticeably longer, which is exactly why they suit slopes and tight soils. They apply water more slowly rather than faster. Their wind resistance is real but does not shorten run time, and sharing a body does not mean sharing an application rate.

Heads along a walkway are throwing water across the concrete during every cycle. What is the first adjustment to make?

• a.Set the arc and radius so spray stops at the turf edge✓
• b.Lower the controller run time on that station by half
• c.Raise the heads on taller risers to clear the walkway
• d.Move the station to an early morning start time

Overspray onto pavement is a coverage problem, so adjusting each head to the correct arc and reducing radius so the pattern ends at the edge fixes the cause. Halving run time leaves the same overspray in every cycle. Taller risers throw water farther onto the walk. An earlier start time hides the waste rather than stopping it.

Why are irrigation cycles commonly scheduled for the hours before sunrise?

• a.Soil intake rate is naturally higher during darkness
• b.Municipal water pressure is lowest and gentler on the pipe
• c.Wind and evaporation losses are lowest at that time✓
• d.Foliage stays wet longer, which reduces plant stress

Early morning brings the calmest air and the lowest evaporative demand, so more of the applied water reaches the root zone. Pressure is typically higher rather than lower at night. Soil intake depends on texture and structure, not on time of day. Extended leaf wetness actually encourages foliar disease and is a reason to avoid evening watering.

A one-inch meter is rated at 50 GPM maximum. What flow should the designer plan the largest zone around?

• a.About 35 to 37 GPM, three quarters of the rating✓
• b.About 25 GPM, exactly half the rating
• c.About 60 GPM, since peak demand is brief
• d.The full 50 GPM, which the meter is rated to pass

Designers hold continuous irrigation demand near three quarters of the meter rating so friction loss through the meter stays reasonable and household demand can occur at the same time. Designing at the full rating leaves nothing for the building. Exceeding the rating is not acceptable at any duration. Half the rating is unnecessarily conservative and drives up zone count.

Where should a pressure gauge be attached to read the static pressure available to a proposed system?

• a.At an outside hose bibb with no water flowing on site✓
• b.At the controller location using a test manifold
• c.At the far end of the existing mainline while a zone runs
• d.At a spray head riser with the zone valve open

Static pressure is measured with no flow anywhere on the service, and an exterior hose bibb near the point of connection gives a clean reading. Reading at an open head or during a running zone gives dynamic pressure instead. A controller is an electrical enclosure with no water connection to test.

A hydraulic worksheet lists losses for the meter, the backflow assembly, the mainline, the valve, and the lateral. Why must the backflow assembly appear on it?

• a.It adds pressure downstream when the checks are clean
• b.It consumes a significant share of available pressure✓
• c.It sets the maximum velocity allowed in the mainline
• d.It reduces the flow the meter is able to deliver

A reduced pressure assembly typically eats about ten to twelve psi and even a double check takes several, so leaving it off the worksheet is a common reason zones run short of pressure. It does not change what the meter can deliver, it never adds pressure, and velocity limits come from pipe sizing rather than from the assembly.

A new commercial landscape exceeds the size threshold at which MWELO calls for a dedicated landscape water meter. What is the purpose of that meter?

• a.To provide a shutoff the fire department can operate in an emergency
• b.To allow the water purveyor to bill landscape water at a lower rate
• c.To keep landscape flow from reducing pressure inside the building
• d.To measure landscape use separately and compare it to the budget✓

Separating landscape flow from building flow is what makes it possible to compare actual use against the calculated water budget and to spot leaks. Rate structures vary by purveyor and are not the ordinance purpose. A meter is not a fire department connection, and metering does not by itself protect building pressure.CA MWELO (Title 23)

A mature oak sits in the middle of a new lawn area. What irrigation approach protects the tree?

• a.Put the tree on its own valve for deep, infrequent watering✓
• b.Include the tree in the turf zone and extend the run time
• c.Place a ring of spray heads at the trunk to soak the root crown
• d.Install a bubbler at the trunk and run it with every turf cycle

Established oaks decline under frequent shallow turf watering, especially near the trunk, so a separate valve allowing infrequent deep irrigation out toward the drip line is the protective choice. Sharing the turf schedule keeps the root crown wet. Heads or bubblers at the trunk concentrate water exactly where crown rot begins.

A bubbler is specified for a newly planted 24-inch box tree. What condition must accompany it?

• a.A check valve so the basin does not drain after shutoff
• b.A finer filter than the rest of the system requires
• c.A watering basin or root ball area that can hold the flow✓
• d.A pressure-compensating emitter installed on the same outlet

Bubblers discharge at a high rate in a small area, so a formed basin or a contained root ball area is required or the water simply runs off. A separate compensating emitter on the same outlet is redundant. A check valve addresses drainage in the lateral, not basin retention. Bubbler orifices are large and need no special filtration.

An older system is being retrofitted from spray heads to inline drip in the shrub beds. Which existing component most often has to be changed at the valve?

• a.The zone needs a larger solenoid to open at lower flow
• b.The zone needs a filter and a pressure regulator added✓
• c.The zone needs its common wire replaced with heavier gauge
• d.The zone needs the control valve relocated above the beds

Drip runs at low pressure and cannot tolerate particles, so a retrofit kit adding filtration and regulation at the valve is the standard change. Solenoids do not vary with flow. Wire gauge is unrelated to converting the piping. Relocating the valve uphill matters only for anti-siphon devices, not for a drip conversion.

How often should the ends of inline drip laterals be flushed on a maintained system?

• a.On a routine schedule, such as each season's start✓
• b.Once at installation, since the lines then stay sealed
• c.Only when emitter output visibly drops off
• d.Only after the filter has been replaced

Fines that pass the filter settle at the far end of every lateral, so routine flushing on a set schedule clears them before they plug emitters. Waiting for visible output loss means damage has already happened. Filter replacement does not remove what is already in the line, and a sealed system still accumulates sediment and biofilm over time.

A crew must locate a buried valve on a system with no as-built drawing. Which method is the appropriate first step?

• a.Energize the station and trace the valve wire with a locator✓
• b.Pressurize the zone and listen for flow at the meter
• c.Excavate along the mainline at ten-foot intervals
• d.Cut the lateral at the nearest head and follow it back

A wire tracer follows the energized valve wire directly to the solenoid, which is the least destructive way to find a buried valve. Random trenching along the mainline damages pipe and landscape. Listening at the meter confirms flow but gives no location. Cutting a lateral creates a repair without narrowing the search.

Which practice makes a valve manifold serviceable years after installation?

• a.Grouping all valves for the site into one continuous trench
• b.Solvent welding the valves directly to the mainline tee
• c.Setting the valve boxes two inches below finish grade
• d.Installing unions or slip fix couplings on each valve outlet✓

A union or repair coupling at each valve lets a technician remove one body without cutting and rebuilding the manifold. Welding valves solidly into the tee forces a cut-out for every repair. Boxes buried below grade cannot be found. Grouping all valves in one trench is a layout choice that does not make individual valves easier to replace.

A soil moisture sensor is added to an existing controller. How does it change operation?

• a.It calculates run times from local reference evapotranspiration data
• b.It adjusts nozzle pressure at each head to match soil conditions
• c.It allows a scheduled cycle only when soil moisture is below a set point✓
• d.It measures flow through the mainline and closes the master valve

A soil moisture sensor reports the condition of the root zone and permits or skips the programmed cycle based on a threshold. Using weather data to compute run times is what a weather-based controller does. Flow measurement and shutdown belong to a flow sensor and master valve. No sensor adjusts pressure at the heads.

An irrigation plan calls for check valves at heads on a slope and pressure regulation at every head. What performance problem do these two details address?

• a.Excess flow demand that exceeds the available meter capacity
• b.Poor uniformity caused by mismatched nozzle arcs
• c.Water waste from low-head drainage and from misting✓
• d.Root intrusion into laterals installed below grade

Check valves stop the lateral from draining out the lowest heads after each cycle, and head pressure regulation stops fogging at high pressure, so together they cut two common sources of waste. Arc mismatch is a nozzle selection issue. Meter capacity is addressed by splitting zones. Root intrusion is a subsurface drip concern handled by treated emitters.

A designer is deciding where to place the point of connection for a new system. Which location is generally preferred?

• a.At the farthest hose bibb so the run to the valves is shortest
• b.Downstream of the building pressure regulator inside the garage
• c.At the water heater cold inlet where a tee already exists
• d.On the service line ahead of the building, downstream of the meter✓

Connecting on the service between the meter and the building keeps irrigation demand from competing with fixtures inside and gives the backflow assembly a clean above-grade location. A connection past the house regulator inherits reduced pressure. A water heater inlet is a fixture supply, not a system connection. A distant hose bibb is undersized for zone flow.

Which statement about installing an irrigation system on a site served by recycled water is accurate?

• a.Recycled and potable lines may share a trench if both are Schedule 40
• b.Recycled water systems are exempt from backflow protection requirements
• c.Recycled water lines are marked with green tape and green valve boxes
• d.Recycled water piping is identified in purple and kept separate from potable✓

Recycled water piping, valve boxes, and identification tape are purple, and the system must be physically separated from potable piping with no cross-connections. Sharing a trench without required separation is not acceptable regardless of pipe class. Green identifies sewer, not recycled water. Recycled water is a health hazard and increases rather than removes backflow requirements.

A newly seeded lawn and an established shrub bed are on the same controller. How should the seeded area be scheduled during establishment?

• a.The same program as the shrubs, with a higher station multiplier
• b.Deep watering twice a week to encourage rooting downward
• c.Brief cycles several times a day to keep the seedbed damp✓
• d.One long cycle each morning to soak the full root zone

Seed germinates in the top fraction of an inch, which dries within hours, so short frequent cycles are correct until the stand fills in. A single long cycle leaves the surface dry by afternoon. Deep infrequent watering suits established plants but kills germinating seed. Matching the shrub program applies water at the wrong frequency entirely.

A residential system is set with a single program watering every zone every day for ten minutes. What is the main weakness of this schedule?

• a.The master valve cycles too often and will wear prematurely
• b.Zones will overlap and reduce pressure at the far heads
• c.Every hydrozone receives the same depth regardless of its need✓
• d.Total runtime exceeds what most controllers can store

A uniform daily schedule ignores the differences between turf, shrubs, and drip areas, so some plants are drowned while others stay dry, which is precisely what hydrozoning and separate programs exist to solve. Storage capacity is not a limit at this scale. Master valve cycling is normal wear. Controllers run stations sequentially, so overlap does not occur.

A rain shutoff device is installed but the system still runs during a storm. What should be checked first?

• a.Whether the sensor is wired into the circuit and not bypassed at the controller✓
• b.Whether the controller has enough stations for the sensor
• c.Whether the sensor is mounted below the roof eave for protection
• d.Whether the sensor is rated for the local reference evapotranspiration

Most controllers have a sensor bypass switch or a jumper that must be removed, and a sensor that is installed but bypassed does nothing, so the wiring and bypass setting are the first check. Station count is unrelated. Sensors are not rated to evapotranspiration values. Mounting under an eave is in fact wrong, because the sensor then never gets wet.

Turf on a narrow parkway strip between the curb and sidewalk shows chronic dry edges and stained concrete. What is the durable fix?

• a.Add two more spray heads and shorten the run time
• b.Convert the strip to subsurface drip with low water use plants✓
• c.Change the nozzles to a higher precipitation rate set
• d.Raise the heads and increase operating pressure at the valve

A narrow strip cannot be watered by overhead spray without overspray, which is why MWELO restricts it, and conversion to subsurface drip with appropriate plants solves both the dry edge and the staining. More heads and higher rates add more water to the pavement. Raising heads and pressure increases both drift and overspray.

Which situation calls for a separate zone rather than adding heads to an existing station?

• a.A lawn panel with a uniform slope of less than two percent
• b.A turf area whose heads are all the same nozzle family
• c.A shaded north-facing bed sharing a valve with full-sun turf✓
• d.A bed whose plants share the same mature size and habit

Shade and full sun produce very different water demand, so combining them on one valve guarantees that one area is mis-watered, and splitting the valve is the fix. Matching nozzle families, uniform plant habit, and a gentle uniform slope are all conditions that make a single shared station work well.

A contractor is asked to add a booster pump because static pressure at the meter is only 38 psi. What must be verified before installing it?

• a.That the pump is installed upstream of the water meter
• b.That the pump is wired to the same circuit as the controller
• c.That the purveyor permits pumping on the service and protection is adequate✓
• d.That the pump discharge exceeds the rating of the mainline pipe

Pumping on a potable service can pull down the main and creates backpressure, so purveyor rules and adequate backflow protection must be confirmed before anything is installed. Sharing a circuit with the controller is an electrical detail. Nothing may be installed upstream of the meter. A pump that exceeds the pipe rating would be a defect rather than a requirement.

At final walkthrough the owner asks for documentation of the new system. Which package is most useful for future maintenance?

• a.The soil report and the plant list from the landscape architect
• b.As-built drawings with valve locations plus the schedule and part list✓
• c.A copy of the hydraulic worksheet used during design
• d.The manufacturer catalog pages for the heads that were used

As-builts showing where valves and mainlines actually landed, together with the programmed schedule and the parts installed, are what a future technician needs to service the system. Catalog pages describe products without locating them. The soil report and plant list support planting decisions. The hydraulic worksheet documents design intent but not field conditions.