Rivers are usually polluted, so it has always been safer to use water from underground in Norfolk. Wate is usually found in porous sands or in fissures in the chalk and is prevented from sinking lower by impervious rock such as clay below it. Wells and later pumps operated by hand were the methods of drawing water in North Walsham before the main waterworks started in 1902. Wells in Norwich Road had to be dug to a depth of about 15 metres (nearly 50 feet) where there is a layer of very fine light yellow sand. The problem with this was'that it was only a thin bed of sand and could run dry in the summer. Also since drainage was not advanced at the time, there was a danger of contamination from sewage and other polluted matter. It was necessary to bore down to a depth of over 40 metres to reach supplies sufficient for the growing town in the early years of this century. The water is rich in lime but pure enough to be piped to consumers without the elaborate treatment which water in Norwich gets. The system is now linked to the regional supply and the shortages experienced in the late 1960s are now less acute.
There are several large users of water in North Walsham; the market gardeners need it for irrigation the cannery and the North Walsham Laundry are all large users, with several private bores in use. House holders now use much more water than 50 years ago and the population of the town has also doubled. In addition the surrounding villages are now linked to the mains and require large quantities.