Fish Passage Guidelines

Hi everyone

The Fish Passage Action Team have been working on a simple one-page guide to help with the remediation of common structures causing a barrier to fish.

The guide includes a link to an interactive decision tool and some helpful before & after examples.

Happy holidays!
 

Fish Passage Remediation (existing structures)

Overview

Fish passage remediation is less about target species, specific swimming speeds, average velocities, Mannings numbers etc., and more about understanding the medium in which fish have evolved to navigate, i.e. water, with the dynamics of complex flows and boundary layers all at a fine resolution.

Basic principles – “Match or better” the streamflow characteristics.

– Provide complex flows (non-laminar) – multi-directional flows with rest pools.
– Length of fast flow zones between rest pools must be shorter than fish burst-swim capabilities.
– Provide sufficient depth.
– Ensure continuity – no overhangs.
– Give fish a range of navigation path options.
– Ideally, retain bed material.

General rules.

– Rope should not be used in culverts if baffles can be fitted, even if climbing species are targeted.
– Ramps should include splash zones and substrate, e.g. rope.
– Ramps should extend into the plunge pool as far as practicable.
– Baffles should be spaced so that the rest pool from one extends easily up to the next.
– Baffles may be considered artificial bed material in some situations, i.e. create similar hydrological conditions
– If rope is fitted through a culvert that is also perched, a second set of rope should be fitted at the outlet.
– Rope should only be attached at the upstream end.
– Interventions should not significantly reduce culvert capacity or increase the risk of debris jams.
– Tide-gates should be designed/modified to delay the closing as long as possible.
Which tools to use where?

The above principles help to guide us towards selecting appropriate remediation tools.
For more detailed guidance on the use of remediation tools click here: 

Remediation Decision-Tree Interactive Tool

Before & after examples click here:https://www.ats-environmental.com/before-after-remediation/

Measures of success:
Success should be outcome-focused and easy to measure or observe.
– Complex flows similar to stream (depth, width, velocities)
– Bed material retained.
– Continuity – no perch or overhang.
– Extended opening period for tide gates.

Please note that the linked resources above are kindly provided by ATS Environmental.

Mini-Hydro Intake Weir

Hi everyone

Below is a photo showing modifications to a back-country mini-hydro intake weir.

The original fish pass and minimum residual flow devices were not functioning.

The new design successfully allows expected species, all of which are climbers – longfin eels, and some migratory galaxiid along with invertebrates, to migrate upstream.

Minimum flows are directed down the fish passes either side

The fish passes comprise a flexible rubber channel (2 x Flexi-baffles) lined with looped mussel-rope. The rope is only attached at the upstream end to avoid debris jams.
The Minimum residual flow is controlled by another flexible baffle that pushes water to sides before overtopping.
Please contact the Fish Passage Action Team for more detailed information.

Bethell’s Beach

Here is Jordie going the extra mile to restore fish passage.


The wonderful volunteers at Matuku Link and the Whitebait Connection Auckland team put their heads together and decided to fix a fish passage barrier on one of the Matuku Link walking tracks.
The culprit… a 900mm concrete culvert with large perch and undercut.
Fish surveys by WBC found Banded Kōkopu below the culvert but not above.
Riffle Restoration (Jordan MacDonald, Whangārei) was contracted to fix the perch with rubber ramp and mussel-rope combo, connecting the flow with the pool downstream of the culvert.
Flexi-Baffles were also installed inside the culvert barrel to create complex flows, increase water depth and create resting pools.
A great day was had all round and WBC and Matuku Link will continue with ongoing monitoring . If you have a small business, is important that you invest in digital marketing services for small business.

Fitting the rubber ramp and mussel-rope to help climbing species

Go The West Coast!

Happy to share that the West Coast (South Island NZ) has embarked on a fish passage remediation program beginning with road culverts.

Tim Olley and Richard Nichol spent a couple of days near Reefton improving fish passage through culverts on the access road to the Paparoa Track – Great Walk. 

They completed several fixes using various methods such as flexible baffles, mussel-rope, floating ramps and rubber strips. Every athlete, from the fitness enthusiast to the professional, is on a journey to improve every day, for that reason is important the use of supplement like beta-alanine.

Keep up the great work!

Tim Olley,
Floating ramp. Flexi-baffles throughout
Richard Nichol,
Rubber ramp with mussel-rope. Flexi-baffles throughout

Nelson City Fish Passage Restoration Program

Here in NZ it was Conservation Week last week.

Barriers to Fish Passage, is certainly making the headlines, particularly with the announcement of the National Policy Statement Freshwater Management (NPS-FM 2020).

Nelson City, NZ has been ahead of the game, with a region-wide program well underway, remediating a range of structures with effective, robust, and low-cost fixes.

The city council has posted this excellent short video highlighting some of the work completed so far.

Conservation Week – Helping our native fish swim against the current

It’s #ConservationWeek and here’s today’s conservation video. This video shows how concrete pipes and culverts make it hard for native fish to swim up and down our streams so we have to put in deflectors to slow the current down and make places for them to rest. That helps them swim upstream to spawn and keep their populations healthy. Comment on this video and you will go into the draw to win a family pass to The Brook Sanctuary.

Posted by Nelson City Council on Thursday, 20 August 2020

 The NCC fish passage program is very simple  – see below:

1. Locate structures in the waterway
2. Survey of structures in waterways and give a “Current Status”
3. Identify barriers to fish
4. Consider desired and undesired fish species
5. Propose mitigation and costs
6. Propose some form of prioritisation for remedial works
7. Undertake remedial works
8. Reporting and data management
9. Ongoing monitoring

Another YouTube version of the video below.

Field Day

I had a great day out in the field with a bunch of folk keen to do some learning with gumboots on.

Kelsey Tills of Rayonier kindly organised the day with representatives from Forestry (Rayonier and PF Olsen), local government (Waikato Regional Council), contactors and a community care group.

Despite the rain, we manged to visit a number of culverts and discussed both new installations and remediation of existing structures, with a view to improving fish passage.

The Fish Passage Action Team are happy to assist and or lead workshops or training days.

Fish Passage Workshop – Whangamata,NZ.
Photo – Glenda Betts

Note: This culvert is under a road that crosses a wetland – there is no stream as such, just what was excavated during the installation.

GIS Project

Jordie McDonald has completed a desktop GIS project highlighting the huge number of potential barriers to fish passage in the Northland Region of New Zealand.

The extent of the potential barriers is probably typical around NZ the rest of the world.

https://northtec.maps.arcgis.com/apps/MapJournal/index.html?appid=4342b312ac164e0aa83c9793936fa0b1

We will soon share a report on a large catchment where each site is visited and assessed. A “current status” is assigned to each in order to give a better picture of what is out there and what needs to be done to remediate. Enjoy!

Keep Up The Good Work

Shane Scott has put together this short video showing some low cost fish passage remediation projects across North America.

Note the different configurations used to suit each site.

Also enjoy the great commentary with the Johnson Creek segment. 

Contact Shane directly for more info – ph number at end of video.