River Mun

Mun
Mundesley Beck
River
River Mun Gauging Station
Country	England
Region	Norfolk
Source
- location	Northrepps
- elevation	45 m (148 ft)
- coordinates	52°54′00″N 1°20′25″E / 52.9000°N 1.3404°E / 52.9000; 1.3404
Mouth	North Sea
- location	Mundesley
- elevation	0 m (0 ft)
- coordinates	52°52′36″N 1°26′28″E / 52.8767°N 1.4410°E / 52.8767; 1.4410Coordinates: 52°52′36″N 1°26′28″E / 52.8767°N 1.4410°E / 52.8767; 1.4410
Length	8.9 km (6 mi)
Location of the river mouth within Norfolk

The River Mun or Mundesley Beck is a river in the north of the county of Norfolk, England. The source of the river can be found in the Parish of Northrepps. The river finally runs into the North Sea in the village of Mundesley.

The source of the River Mun can be found next to Craft Lane, close to Furyhill plantation between Northrepps and the hamlet of Frogshall. It runs in a south easterly direction through a wooded valley and passes under Craft Lane close to Frogshall Farm House. From here it runs through woodland for a short distance and into a large pool called Little Broad. From Little Broad, still in woodland, the river falls over a weir and into some marshy woodland known as Osier Carr. Deep in the heart of Osier Carr Freshwater mussels (Bivalvia: Unionidae) can be found. The mussels are filter feeders, removing phytoplankton and other suspended particulate matter from the river. This removal of suspended matter from the water is often considered ecologically desirable, as it reduces phytoplankton blooms and in the treatment of drinking water. The river now passes under another lane from Sidestrand. From here the river feeds a system of ponds and sluices in an area known as the Grove. Many drains feed into the river here. The river now turns almost south and passes under another lane called Cromer Road and crosses countryside towards Ash Tree Farm and Ash Plantation. The river now widens slightly and begins to cross open countryside, slowly turning south east again. Along this section the Mun runs adjacent to several small reservoirs and ponds and drains.

At Gimingham the river flows into a series of Mill Ponds. These ponds fed Gimingham watermill (Nat Grid Ref TG28663690) which is the first of two mills that stood on the river. The Mill dam once held back a 20-acre (81,000 m²) broad fed by the River. The water ran under the Mill street to reach the waterwheel, which was probably originally overshot. There has been a mill at this point since the time of the Domesday book. The last mill to work here was built of local brick and flint brought in from local beaches. The original waterwheel went fairly early on, first being supplemented by steam and then replaced by a turbine with half twist drive in 1912 and then later by diesel engines, although water was still used for cooling them. The mill carried on working until 30 November 1976, using its diesel power to mill animal feedstuffs. The watermill was worked in conjunction with the nearby Gimingham postmill until 1877. The original heavy diesel oil engine has been carefully preserved and stands on Mill Street just below the old mill. Gimingham Mill Lake is a very popular fishing location. In the lake, pit and river, Bream, Carp, Tench and Roach can be caught. From Gimingham the river cross more open farm land now heading east, passing on its left Mundesley Hospital which was refurbished in 1997 and is now the Diana Princess of Wales Treatment Centre for Drug and Alcohol Problems. Where the road leading up to the hospital crosses the River Mun, the Environment Agency has a Water Resource Management gauging station. From here the river begins to skirt the southern side of the coastal village of Mundesley.