Glossary

½ or ¾ inch tubing: A low-volume distribution component typically used to bring water from a riser into a hydrozone. Self-piercing emitters punch directly into this tubing.
¼ inch tubing: A low-volume distribution component typically used to bring water directly to the plants (in runs no longer than 5 feet). Also known as “spaghetti” tubing.

Automatic connection: Refers to the either the irrigation or hose connection to the cistern operated with an automated irrigation controller.

Backflow preventer: A device that stops water in the irrigation system from backing up into the water supply during a sudden loss of pressure. Required by code in one form or another, these devices protect public health and safety by preventing water system contamination and pollution.

Cistern: A receptacle for holding water or other liquid, especially a tank for catching and storing rainwater.

Clock: See “ controller”

Controller/Timer/Clock: A device used to program days of the week, times of day and number of minutes, to automatically irrigation your landscape according to seasonal weather and plant needs. Controllers communicate with your valves via field wiring.

Downspout: A downspout drains all roof runoff water directly out of the pipe into the rainwater harvesting tank.

Drip irrigation: An irrigation system in which water is applied directly to the root zone of plants by means of applicators (emitters, porous tubing, perforated pipe, etc…) operated under low pressure.

Drip emitter: A low-volume emission device that delivers water at low flow rates. Drip emitters are used to apply water directly to an individual plant rootzone.

Filter: A device used to screen dirt and debris from the water. Filters are important in low-volume systems because the small emitters can easily become clogged.

Flow: The amount of water, usually measured in gallons per minute or gallons per hour, that can pass through an irrigation system.

First Flush System: A device or length of capped pipe that diverts the dirtiest or foulest first flush of water running off a catchment surface away from a cistern.

Flow meter: A device that measures the amount of water flowing through a pipe.

GPH: An abbreviation for Gallons Per Hour, a measure of the flow of water through an irrigation system. GPH is typically used to measure flow in low-volume irrigation systems.

GPM: An abbreviation for Gallons Per Minute, a measure of the flow of water through an irrigation system. GPM is typically used to measure flow in conventional irrigation systems.

Gutter: a long hollow device that is attached beneath the edge of a roof to catch and carry rain water off of the building.

GPD: An abbreviation for Gallons per Day as required by landscape plants, and used to formulate irrigation schedules.

Hydrant: See “multi-outlet emission device.”

Hydrozone: A group of plants with similar water requirements served by one irrigation valve.

Horticulture: The art or practice of garden cultivation and management.

Hose bib: An outdoor water faucet, or shut off valve, that controls the release of water.

Landscape: All the visible features of an area of land, often considered in terms of their aesthetic appeal.

Low-volume irrigation: A type of watering system (drip, bubblers, microspray, soaker hose) in which a precise amount of water is applied directly to the rootzones of plants.

Mainline: Pressurized pipe that runs from the water source to the valve manifold, generally under continuous pressure.

Manifold: A constructed base of PVC pipe consisting of “tees” spaced at specific intervals onto which individual valves are attached.

Runtime: The number of minutes a zone on your irrigation system should run each time you water. Runtimes should be adjusted each month, as well as any time there is significant rainfall.