The Canterbury Plain is flat, East Anglia is almost hilly by comparison. At a time when the land was being parcelled out for farming, some enterprising engineers and surveyors constructed an elaborate series of canals, channels and controlled irrigation races (water channels) around each farm. This extraordinary scheme still exists today and I had a detailed tour of the system with one of my nephews who is currently managing it, along with a regular team of Race Managers, called Racemen.
Starting at the canal
The weirs are designed to slow the flow of water along the natural drop, in order to stop wear and tear on the banks, causing erosion and damage. At the next stage the races are spread out to the various farms,
operated in the 1930s by hand, and still to some extent today, by the Racemen, a team who each have responsibility for several farms in one area. These then feed into the farmers’ channels at which point they become the responsibility of the farmer,
There are various ways to spread the water. Large pivoting gantries, working from a central pivot in a curved sweep, and which can be up to half a mile long, spray across or around the field; other types move up and down a field while attached to a parallel hose, it will take three to four days to complete a full watering cycle;
or there is also a smaller mobile sprayer attached to a dragging hose, and moved by tractor. These are quite vulnerable to strong winds, as are the larger gantries, but Meccano-like, they can be repaired with sections as long as they are not too damaged.
The main disadvantage of the tractor drag being that it can take up to twelve days to cover the whole farm, known as the twelve-day-return. The farmer therefore needs to calculate carefully, balancing out the possibility of rain – in which case the crops may get too much water, with the possibility of no rain, in which case a field may not get water for nearly two weeks.
Some farms have ponds, which means they have a modicum of control regardless of rainfall or rationing and the company itself also has storage ponds for when demand is increased due to a lack of rain, or decreased due to a seasonal change.
Changes in the farming practice in the Canterbury Plain is also having it effect on the system. A great deal of arable land is being turned over to animal husbandry, and the increase in the profitability of dairy products has led to a greater number of cattle, over either sheep or crops.
Today much of the system is being upgraded to an underground supply, still fed from the same sources but being piped on to the farms. The principal advantage of this development is being driven by the benefit of harnessing gravity to supply water pressure in preference to using electrical pumps. This will also greatly improve the farming environment, the races and their supply ‘lanes’ take up a lot of room which in the new system will be usable land; it will hugely reduce evaporation loss and should reduce seasonal watering over-use as described above.