Essex Rivers Hub

Blackwater; Grigg’s Farm, Bradwell

Natural river structure with meanders, silt bars and large amounts of reed present. The banks have lots of natural vegetation but it is used as a Cricket Bat Willow plantation and during the survey we noticed areas of the bank at regular intervals had been damaged when harvesting the willows.

The area (land use)

The dominant land use for this stretch of river is rough grassland and woodland.

No livestock were recorded.

Channel characteristics

The river channel consists of mainly silt, and riffles are present in the downstream section only.

At the time of recording the flow of water was slow and the channel was 10-20m wide and <0.5m / 0.5-1m / 1-2m in depth.

For most of this stretch the channel profile is steep.

Bankside trees were frequent, marginal plants and in-channel plants are dominant. Woody debris was noted to be rare.

Engineering

The channel has not been straightened and man-made enhancements are present in the upstream section only along this stretch of river.

Field drains were recorded as present and barriers / culverts are Present in the upstream section only.

Condition

Areas of trampling / poaching were absent and areas of erosion were absent at the time of the survey.

Wildlife

During the survey the following was seen or heard: Mallards, Pheasants and Fallow Deer.

Additional Information

There were areas of overland runoff in the form of drainage ditches. The water was a brown colour during the surveys but this may have been due to recent rainfall. It is likely that Himalayan Balsam grows in this area but would not have been visible at the time of the survey due to the presence of other vegetation.

In some cases a vehicle had been push down the bank into the channel, depositing large amounts of silt into the channel. Burning of the unwanted parts of the willow was witnessed on the bank but this seemed to be of sufficient distance from the channel to prevent contamination.

RBD/catchment/river/tributary

River Blackwater

Date completed

Apr/May 2014

Upstream Grid ref

TL8301422164

Downstream Grid ref

TL8417222210

Website key stakeholders:

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Design by LTD Design Consultants and build by Garganey Consulting based on an original concept by Herts and Middlesex Wildlife Trust