Fairham Brook Improvement Projects

The Fairham Brook is 28.4km in length, starting at Old Dalby, Leics and it drains approx 80km2 of land.

In terms of management it has three separate sections – the upper reaches (responsibility of the Lead Local Flood Authority), the middle section which is maintained by the IDB (8.2km) and the EA maintained section which includes the Fairham Brook Nature Reserve and extends to the confluence with the River Trent.

Wildlife

There are no current known populations of water vole and mink is known in much of the catchment. The brook itself supports Brown Trout, Chub, Dace, Eel, Gudgeon, Miller’s Thumb, Minnow, Perch, Pike, Roach, Stone Loach, Tench and Tiddler, Swan Mussel (recorded in 2011). Kingfisher. Grass snake.

Nationally notable Cream Bordered Green Pea Moth on the nature reserve. Also on the reserve is alder buckthorn, pignut, pepper saxifrage, 11 species of dragonfly – including broad bodied chaser, 20 species of butterfly – including wall and small heath have been recorded, snipe, barn owl, woodcock all recorded, amongst other species.

IDB managed watercourse

Deepening and straightening of the brook’s channel by the Fairham Brook Internal Drainage Board (FBIDB) took place in the early 1980s. The work was carried out primarily to allow drainage of surrounding low lying agricultural land, which has since been used for arable production. It also served to quickly take flood water away from Bunny village. This modification of the channel means that it currently has low ecological value through the straightened section. The water course from Fairham Brook Reserve in Clifton to Bunny is now under the care of the newly created Trent Vale IDB and they have started to change the situation with a policy of reduced bankside and riverbed management

It was a long term aspiration of Nottinghamshire Wildlife Trust and the Environment Agency to improve the Brook, EA and NWT in partnership with FBIDB put together a project to address the issues but for a long time it wasn’t possible to get any funding.

Water Framework Directive

WFD is an EU directive which requires that all water bodies reach good ecological status (or for those water bodies that can never achieve this – good ecological potential) by 2027. Essentially this means looking at water bodies in a more holistic manner than we have traditionally, and assessing them based on chemical quality (phosphates, nitrates etc.), biological (fish, plants, invertebrates etc.), river morphology (has it been straightened/culverted etc.) and physio-chemical (temperature, nutrients etc.).

Through the need to implement the WFD, money has been made available for projects which tackle the issues highlighted above and bring the water body into better status.

Fairham Brook WFD Project

This is a three year project funded by Defra via EA, and is being undertaken by NWT in partnership with the EA and the IDB. As the project started the IDB’s were amalgamated and it is now the responsibility of Trent Vale IDB;

Year 1 – feasibility study (carried out by the IDB) and landowner engagement – any changes to the channel found not to affect conveyance of water.

Year 2 – project identification and landowner liaison.

Year 3 (this year) – delivery of capital works

The Projects

Installation of pre-planted coir roll. This creates pinch points and speeds up water flows, allowing the riverbed to be scoured, uncovering gravels which are used by breeding fish. Within a short space of time – 2/3 weeks – this was already occurring. There was no risk of increased flooding as the water travels over the top. 300m of rolls have been installed in two locations – one in Bunny and one in Gotham (both on private land).

Installation of a cattle drink. Cattle drinking from streams and rivers ‘poach’ the ground mobilising soil and increasing the amount of soil in the water body. This not only increases nutrients within the water body, it also covers up the gravels needed for fish spawning and decreases channel depth where it is deposited. The provision of cattle drinks – fenced areas with hardstanding which still allow cattle to drink from the river but without the issues of poaching – stops the loss of soil (valuable resource), lessens sediment inputs which in turn create better habitat for fish spawning and also decreases the nutrient lvels entering the river as suspended solids.

Installation of a rock ramp. This will allow fish passage over a weir –  some species of fish are unable to travel upstream to spawning grounds as weirs are impassable to them. This will be achieved by lowering large boulders down from the railway bridge and placing them to create a tiered ramp leading up to the weir.

 

Berm creation. These are areas of permanent vegetation slightly above the normal water level, often on bends or meanders and in this case they will prevent erosion on the opposite bank as flood waters go over the top rather than hitting the other bank with increased force.

Fairham Brook Nature Reserve

Fairham Brook is a moderately-sized nature reserve at the southern extremity of Nottingham City, on the south-eastern edge of Clifton. The reserve is a long, thin sliver of land in the floodplain of Fairham Brook, which is a northward-flowing tributary of the River Trent. At 10.8 hectares this is one of the largest nature reserves in the City of Nottingham.

The northern, widest part of the site comprises patches of neutral grassland amongst significant amounts of scrub; some of the latter having developed from hedges which used to sub-divide the area into a number of small fields. The southernmost end of the reserve supports a similar range of grasses and tall herbs. The ground appears to be no wetter than further north, but this is the area where common reed is at its most abundant.  A moderate amount of scrub is also present, mainly in the form of scattered hawthorn bushes. The central part of the site is mainly open grassland, but with quite a lot of scrub near the river.  The recent creation of a series of small ponds in the northern half of the reserve has mitigated to a small extent the major detrimental effect of falling water table in recent decades.

Prior to 1970 the soils were frequently waterlogged, which led to the development of open fenland vegetation, when grazed.  Today the water table has dropped drastically, and the site is only wet for short periods during occasional flash floods.  This major change is a direct consequence of deepening and straightening of the brook’s channel by the Fairham Brook Internal Drainage Board (FBIDB) in the early 1980s (East Midlands Environmental Consultants Ltd., 1996).

Sick is an old word for a brook, and therefore sick grassland was permanent pasture/hay meadow along a brook or other watercourse, within the open field arable system. The presence of such grassland at Fairham suggests strongly that for a very long part of its history (until about 1790) the site was subject to common grazing plus hay-making. This management is entirely compatible with the development of botanically-rich grassland. The site continued to be grazed until the 1950s, thus maintaining a mixture of species-rich fen and grassland. There has been no agricultural management of the reserve in the 50 or so years since the last tenant farmers managed the land (the Beecroft family); consequently the botanical richness has almost certainly declined, albeit slowly.

Owned by the Department of Leisure and Community Services within Nottingham

City Council (NCC), the site has been managed and tenanted by Nottinghamshire

Wildlife Trust (NWT) since 1970.

FBNR Project

What is fen and why is it being lost? Fens are mires, usually on peat, that receive water and nutrients from the soil, rock and ground water, as well as directly from precipitation. Classification of fens is quite complicated, depending upon the direction of water movement through the peat or soil, and whether the water is acidic (poor fen) or calcareous (rich fen).

The distribution and extent of floodplain wetlands has diminished markedly in recent decades, due to drainage works associated with agricultural intensification. Development of floodplains for housing and industry has also taken its toll. There is now increasing awareness amongst planners and land developers that existing fens, marshes and swamps need to be conserved, and others created, because these habitats perform a vital function in regulating water flow and reducing severity of floods. This function will be increasingly important if expected climate change takes place, namely increased rainfall, and more intense rainfall events.

What do we want to do about it at FBNR?

FB NR contains relict fen – peat is still present and the site still retains some wet areas. An artificially dug pond holds water throughout the year. There are lots of trees and scrub present on site, with pockets of more fen like vegetation – reeds etc, in amongst. The water table in the reserve dropped due to deepening of the brook and drainage from the housing estate. Although the top peat layer still retains some water, there is a real danger of all the interest being lost. Holme Fen in Cambridgeshire is a good example of this – the surrounding land was drained for agriculture and over time, the peat layer here has dried out and shrunk – since 1851 the land level has dropped by 4m.

The project aims to retain water on site through the reduction in scrub and tree cover – lessening the evapotranspiration (water loss through vegetation using it) effect and therefore reducing some of the drying out. In addition a figure of eight ditch will be dug which will take water from the brook at times of high water levels (and allow it to flow back out again when full), and transfer it across the fen area. This will also connect to some deeper ponds. All of this will not necessarily increase the wetness of the peat, but it will allow more water to be retained within the area.

As all the spoil created will be removed from site, the creation of ditches and ponds will provide increased flood water storage in this area. This is particularly important as the feasibility study conducted by the IDB showed that it didn’t matter what happened in the channel, the factor that caused flooding was the bridge under Green Lane – where the brook flows out of the nature reserve. By creating water storage before the bridge, this may help to ease problems up stream/

Some of the work has already taken place – scrub clearance, topographical surveys etc. and to avoid damaging the peat layer in the winter, the ditches and ponds will be created in autumn 2015.

Ruth Testa NWT Wetland Projects Officer