Prevent water pollution when working in or close to water

When you work in or near watercourses, it is important that run-off from your site does not contain grass clippings, soil or sediment.

If these pollutants enter a stream or river it can have serious effects on the life in it.

  • Insects living in the bed of the watercourse can be killed through lack of light and oxygen and change in habitat.
  • Fish may be killed when sediment blocks their gills.
  • Sediment deposits on the bed of a watercourse can prevent fish spawning.
  • Additional nutrients from grass clippings in the sediment cause excessive weed growth.

What you must do

In Northern Ireland you must have consent from the Rivers Agency before you place structures in any waterway that are likely to affect its drainage. Contact your local Rivers Agency office for further information.

Northern Ireland: Rivers Agency Area Offices

DAERA has produced a handbook is for landowners and people and organisations involved in carrying out activities that may alter the physical characteristics or flows of rivers and other waterbodies. The activities covered include dredging and substrate addition, removal of bankside vegetation, bed and bank reinforcements, flow manipulation and culverting.

DAERA: Surface Waters Alterations Handbook

In Scotland, if you carry out building and engineering works in inland waters or carry out activities close to waters that could significantly affect the water environment, you must either:

  • comply with certain general binding rules (GBRs) which apply to low-risk activities
  • register your activity with SEPA
  • obtain a licence from SEPA.

In Scotland any static plant or machinery used within 10m of any:

  • river
  • burn
  • canal
  • ditch
  • loch
  • wetland
  • coastal waters

must be placed on a suitable drip tray with a capacity equal to 110% of the capacity of the fuel tank that supplies the equipment. You must make sure that the equipment you use does not leak oil.

Empty drip trays regularly to make sure that they can contain any spills.

SEPA: CAR Practical guide

SEPA: Silt control while dredging 2015

Guidance for Pollution Prevention (GPP) 5 contains guidance on measures you can take to avoid causing pollution during building and engineering work.

GPP5 Works and maintenance in or near water (Adobe PDF – 782KB)

Good practice

If you pollute the water environment, you are probably committing an offence.

You should only strip land of vegetation when it is absolutely necessary. You should carry out the work in short sections to avoid bare earth being exposed for long periods of time. This should help to minimise the risk of run-off, soil erosion and silt getting into watercourses.

  • Use buffer strips (strips of land where the vegetation is not disturbed) along the edge of watercourses to avoid run-off containing pesticides or soil.
  • Where possible you should work across slopes, rather than down them. This will help to minimise the risk of soil erosion.
  • Use earth banks and cut-off ditches to channel the contaminated drainage away from surface waters and drains.
  • You should divert clean water away from un-vegetated areas.
  • Plan ahead and carry out operations leading to bare or disturbed soil in periods of dry weather.
  • Ensure that dirty water does not enter surface water drainage systems.
  • Ensure that sediment does not clog porous paving, filter drains or other sustainable urban drainage systems.
  • Ensure that grass cuttings and other cut vegetation do not enter the water environment.
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