I spy...........a discharge

The environment team is currently leading on a national project to survey and plot discharges going into our canals. The hope is that we will pick up any unauthorised inputs, which could impact on water quality.

One of the issues that I deal with on a regular basis is water pollution incidents, which can range from oily sheens on water to large, unregulated industrial discharges. This can impact on the water quality and in turn the animals which use the canal, as it can lead to reduction in dissolved oxygen levels which they need to breathe and in some cases can cause them harm.   

The survey is intended to pick up unauthorised discharges. We allow some discharges into our canals and rivers, but these must be agreed in advance with the Trust and the Environment Agency. 

Unauthorised discharges can include:

  • Misconnected drains (instead of water going to underground drainage and away to sewer, the discharge pipe is wrongly connected to a pipe which discharges into the canal)
  • Drainage from industrial units/businesses,
  • Rural drainage, with the potential to introduce high levels of nutrients

A lot of the time people are oblivious to the fact that water from their sites are discharging into the canal, they just assume it is going to the sewer.

For the South Wales and Severn area, I decided that the Droitwich canal would be the first to be surveyed.  As it has only recently been restored, I thought it would be useful to get up to date information.

Accompanying me on the survey was Andrew, our placement student, who had undertaken similar surveys on the Birmingham canals. When we saw a discharge, we noted GPS co-ordinates, the pipe size, construction type, whether the pipe was discharging and what type of discharge (oily, discoloured, clear). I initially thought that because the canal was predominately a rural canal, there would be few discharges to note, but I was proved wrong, as we found a number. Andrew and I were only able to walk ½ of the Droitwich. So a few weeks later Andrew and a couple of volunteers, who had come forward as part of a national volunteer scheme, completed the Droitwich survey. A big thanks to them, as the information they all collected will prove valuable. 

The data has been sent to our GIS team who are uploading it onto a national database.  We will be reviewing the data in the coming months, to determine which are authorised/unauthorised and if there are any problematical discharges we need to follow up with the Environment Agency. The local Waterway team have also expressed an interest in using the information.      


Last date edited: 25 March 2014

About this blog

Sara has been with the Trust for 17 years, working in the environment team. She is a senior environmental scientist and will cover waste and water quality issues. She works closely with the South Wales and Severn Waterway team but her work will also pick up national issues, such as the Water Framework Directive.


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