Glossary of Irrigation Terms

A graph which is unique to a particular water pump. Points plotted on the curve demonstrate the capacity the pump will be capable of delivering across a range of different metrics, including the total dynamic head (TDH), which represents the water pressure and the gallons per minute (GPM), which reflects the flow rate. The performance curve can be used to find out whether a pump is suitable for a specific system.

A measure of the speed at which water applied to an area through irrigation will move through the soil, based on factors like density and texture. If irrigation is applied at a rate which is faster than the soil is able to absorb it, then water will be wasted, resulting in pooling, run off and soil erosion. Knowing the permeability of a specific area is key to delivering tailored irrigation.

A chemical agent introduced to a landscape in order to control or eliminate particular organisms. Pesticides might take the form of herbicides, fungicides or insecticides. If an irrigation system delivers water at a rate faster than the soil is able to absorb it, any pesticides present my contaminate ground and surface water.

A measure of the acidity or alkalinity of water, in particular of a water source for an irrigation system. The pH scale runs from 0 to 14, with a lower number meaning more acid in the water and a higher number more alkaline. A pH number of 7 means the water is neutral and completely pure, while high alkaline water is often called ‘basic water’.

In meteorology, precipitation is what happens when water from the atmosphere falls from the clouds, to the surface of the earth. This can be in the form of a liquid or solid state - from rain, snow, and sleet to hail. The small drops of condensed water that form clouds are too small to fall to the earth but when certain conditions prevail, they fall as precipitation. You might be interested to know that one-inch of rain falling over an area of one acre of land results in a colossal 27,154 gallons of water! (Our thanks to the US Geological Survey for that piece of information).

A pump converts mechanical energy into hydraulic energy. In irrigation terms, water pressure and/or flow is created or increased.

PVC is polyvinyl chloride, a thermoplastic polymer, it is one of the most widely used plastics worldwide. It's durable and long-lasting, very dense with excellent tensile strength. It is suitable for irrigation piping in smaller projects where less flexibility is required (for example in bends) and where there is less danger of fluctuations in pressure and movement around the pipe in-situ.