Irrigation Systems in Claremont: Valves, Controllers, and Drip Lines

Irrigation is the most-run mechanical system on most Claremont properties. It cycles more often than the furnace, moves more water annually than rainfall does, and almost nobody inspects it.

That combination makes it worth understanding as HARDWARE rather than as gardening. A failing irrigation system does not just cost water and plants; it is one of the most common sources of the moisture problems that damage foundations, crawl spaces, wood structures and masonry. This piece extends the Claremont home maintenance guide into the system that runs while you are asleep.

The parts, and what each one does

Water leaves the house supply through a dedicated line, passes a backflow prevention device, and reaches a set of VALVES, usually grouped in one or two buried boxes. Each valve serves a ZONE. A CONTROLLER opens each valve on a schedule. Downstream of each valve is the delivery hardware: spray heads, rotors, or drip tubing with emitters.

Knowing that chain lets you localize almost any fault. A problem affecting every zone is upstream - supply, main line or controller. A problem affecting one zone is that zone's valve or its piping. A problem affecting one plant is an emitter or a head.

Valves, and the failure that runs all night

Valves are the components that fail most consequentially, because a valve that does not close keeps watering after the cycle ends.

The signs are readable. A zone that stays wet, or a chronically soggy patch, when the controller is off. Water audibly running with no cycle scheduled. A meter dial that keeps moving with every fixture in the house shut. A valve box holding standing water.

Diaphragms wear, grit holds a valve open, solenoids fail, and wiring corrodes at the splice. These are repairable components rather than replace-the-system events, but a weeping valve deserves attention the week you notice it - it is silently delivering water to one spot continuously, and continuous water against a foundation, a post base or a masonry wall is exactly the condition the foundation guide asks owners to avoid.

Spray heads and rotors

Heads are the visible half and the easy half. What goes wrong is mundane: nozzles clog with grit or mineral, heads sink below the grade of a growing lawn, mowers and cars break them, seals fail so a head weeps at its base, and arcs drift out of adjustment.

Two adjustment faults matter beyond the plants. Heads throwing onto a wall, a fence, a post or a deck skirt create a permanently damp zone in an otherwise arid yard, which is the origin of a surprising share of wood decay and pest findings. And heads watering pavement are pure loss - the water lands where nothing can use it and runs somewhere it was not meant to go.

Low head drainage is the other common annoyance: after a cycle, water in the pipe drains out through the lowest head on a slope, leaving a wet spot and an empty line. Check valves in the heads address it.

Drip, and the maintenance people skip

Drip irrigation is the right answer for most planted beds in this climate, and it fails differently from spray. Because it is quiet and often under mulch, it can be broken for months without anyone noticing until a plant dies.

The failure list: emitters clogged with mineral or debris, tubing cracked by ultraviolet exposure where it sits above mulch, tubing chewed by rodents, fittings pushed apart by pressure, and lines buried under years of added mulch so nobody can find them.

Drip also depends on components spray does not: a pressure regulator and a filter. Without them, house pressure damages emitters and grit clogs them. If a drip zone was installed without either, that is a defect rather than a style choice.

The maintenance habit is simple: once or twice a year, run each drip zone and WALK it, looking for dry plants, geysers where a fitting has separated, and wet spots that mean a split. That walk is the entire maintenance program.

Controllers, and the schedule that never gets revisited

Most controllers are set once and left. That is where most waste lives, because a schedule appropriate for late summer is badly wrong for a wet week in winter.

Smart controllers adjust automatically using local weather data, and for a property with several zones the improvement is real. Whatever the controller, a few principles hold: water early rather than in the heat of the day, water deeply and less often to encourage deeper roots, and separate zones by plant type and exposure rather than by convenience.

Also learn the manual override and the full off state. Being able to shut irrigation down completely, quickly, is part of the emergency knowledge covered in the shutoff valve guide, and being able to run one zone manually is how every inspection in this article gets done.

Water providers periodically offer rebates or programs around efficient controllers and landscape conversion. Those change over time, so check current terms with your provider rather than relying on what was true a few seasons ago.

Backflow, and the part with rules

Backflow prevention keeps irrigation water from being drawn back into the drinking supply. It is a health protection rather than a convenience, and depending on the device and the property it may be subject to testing requirements.

Do not modify, bypass or remove one. If a device is leaking, damaged or missing, that is a licensed plumber's job, and questions about testing requirements belong to your water provider or the City of Claremont.

Finding a leak you cannot see

The meter test is the standard method. Shut off every fixture in the house and the irrigation controller, then watch the meter. Movement means water is leaving somewhere, and running the irrigation shutoff separately tells you which side of the system it is on.

Underground main line leaks between the meter and the valves are the difficult case - they can surface far from the actual break, or not surface at all in dry soil. Persistently green grass in one patch, unexplained soft ground or a bill that has climbed without a change in habit are the usual clues, and locating that leak is a job for a professional with the right equipment.

The bottom line

Treat irrigation as plumbing that lives outdoors. Run every zone manually once or twice a year and walk it. Aim heads off walls, posts and pavement. Give drip zones a filter and a regulator. Fix a weeping valve immediately rather than at the end of the season. Revisit the schedule as conditions change, and use the meter to settle any question about a hidden leak.

How the planting itself should be organized is covered in the landscaping guide, and the wider routine sits in the owner's guide. This is general information rather than plumbing advice for your actual system. Anthony Grynchal has been licensed in California since November 2009.