Fish pass approval

Get approval for your fish pass design when building or making changes to a dam, weir or mill.

If you’re building a new obstruction (like a dam, weir or mill) on a river containing migratory fish and eels you may need to include a fish pass. The Environment Agency (EA) will tell you if a fish pass is needed and if so, must approve its design.

The rules also apply if you’re making major changes to an existing obstruction or making it harder for fish to pass an obstruction.

Design a fish pass

You should consult a specialist when designing a fish pass.

Fish passes help migrating fish get past a weir or other obstruction. They must be suitable for the species and size of fish found in the river and should be built where they have the best chance of fish using them.

Get fish pass approval

The steps for approval are:

  1. Submit your fish pass design and description to your local EA office using the fish pass approval form:
    * Application for fish pass approval (PDF, 645KB, 8 pages) * Guidance notes for fish pass approval (PDF, 276KB, 5 pages)
  2. Designs are reviewed by an independent group of fish pass specialists who recommend whether the pass should be approved.
  3. Your local EA office issues approval.

It’s free to apply - allow up to 6 weeks.

Ideally you should get approval for your fish pass design before you start building.

If you don’t get approval you can re-submit your plans when recommended changes have been made.

Provisional approval

If the pass is in an important location (such as a tidal barrage) or is a new design, EA may issue provisional approval.

Final approval may only be given when the fish pass has been shown to be working satisfactorily.


Environment Agency


Telephone: 03708 506 506 call charges

Monday to Friday, 8am to 6pm

Published 16 May 2014