The most common source of water for irrigation is
the potable mains system but there are other
alternatives which should be investigated before a
decision is made.
Under current legislation, any private householder
is entitled to abstract up to 20 M3, (or 4,400
gallons,) daily, from either groundwater or aquifer
resources on their property. If used on the garden,
this represents sufficient capacity to meet the
irrigation demand of a plot of several acres. This
level of abstraction requires
no requirement for any permit from the NRA and
the use of the water is not governed by any
restrictions placed on normal domestic supplies.
There is also no charge made for the water used.
Many older properties have existing wells which are
sometimes covered up or filled in. Where no well
exists, it can be economic to drill a well specifically
for an automatic watering system, providing
geological data is encouraging. An automatic
watering system for a reasonably large garden
could accept the cost of a well up to 40 M. or so
Commercial users, and domestic abstractions over
the above daily allowance, have to be licensed
through the NRA. In most parts of the country it is
unlikely that a licence would be issued for summer
abstraction from a stream or river in order that a
landscape can be watered.
Conversely, in most areas a licence would
probably be issued for the use of groundwater
from a well or borehole. The local office of the
Environment Agency can advise on the
likelihood of a licence application being view
favourably and the BGS will undertake a
desktop survey of resources for a modest fee.
A small charge is levied by the EA for the water,
based upon the licensed quantity, not that
Mains water is charged at a higher rate but,
even on a watered area of half an acre, (so a
total plot size of about an acre,) the annual
charge is likely to be no more than £360.00 at
current rates so costs are not unreasonable. It
is usually necessary for the mains supply to be
metered if a watering system is in use so
anyone proposing to install such a system
should contact their water company for advice.
Officially, garden watering systems are subject to
hose-pipe bans as any water company will
confirm. However, the companies appreciate the
fact that night time use of the automatic watering
actually reduces day-time loading on their
pipework systems and allows them to sell water at
a time when nobody else wants it. It is perhaps
for this reason that ISC has yet to hear of one of
its clients being shut down during a ban, despite
the fact that all of the systems are known to their
local water companies.