Just sharing this article showing great fish passage work done in the Johnson Creek watershed near Portland Oregon, USA.http://www.jcwc.org/north-fork-open-migration-one-step-closer/
Johnson Creek – Oregon
Eels
This short video shows elvers climbing across both smooth and rough surfaces.
The urge to overcome obstacles is powerful and you can see individuals climbing over each other.
The more we watch these creatures, the better we understand their capabilities and limitations when we are considering remediation.
Click here or on the image below
https://www.youtube.com/watch?v=FEQVQIl7dpc
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.
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.
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.
Focus On Maintaining Fish Passage During Low Flows
It is worth remembering that lows flows and shallow water are challenges to migrating fish.
The video below represents remediation to an upgraded urban storm water pipe serving a small tributary of the Maitai River near Nelson, NZ.
The upgrade involved upsizing the pipe and removing the perch at the outlet.
– Base flows of the tributary are approximately 1L/S
– Pipe length 300M
– Pipe gradients range from 2%-12%
You will see an increase in the depth and width of the water along with bed-material beginning to accumulate.
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!
Lessons Learnt 8
The NZ Dept Conservation Fish Passage Advisory Group website has a number of Lessons Learnt describing different fish passage remediation projects.
Tim Olley spent over a year researching and putting together this comprehensive report highlighting the effectiveness of flexible baffles in a long, steep culvert.
We are planning to make a PowerPoint and/or video of this report at some point.
Enjoy.
Click here to view Lessons Learnt 8
RIPRAP
Stop this disaster!
It is now common practice to use large, similar sized, rip-rap (boulders) to manage downstream erosion at structures.
Above is typical example of a recent culvert upgrade where extensive rock armouring has caused water to be sub-surface and spread over a wide area during most flows, making upstream migration almost impossible for most fish.
The rubber strip and rope were added afterwards to try to help with fish passage.
We need your help to share ideas on how to better provide fish passage while still meeting erosion control requirements.
– Discussion Paper-
The challenge – maintaining fish passage through rock armouring, especially during low lows.
Below is a concept that may provide passage for small fish, while still achieving erosion control.
A series of precast channels maintain a flow path that may be completely covered with large rocks, providing gaps remain between individual rocks.
Installation process
- Excavation as part of structure installation
- Suitable geo-textile laid
- Precast channel fitted to apron at outlet. Also baffles fitted on apron
- Rock rip-rap placed either side of ramp
- Channel covered with rock rip-rap
Points to consider:
– Channel design
– Installation
– Cost
– Durability
– Effectiveness (short and long-term)
– Planting
Brook Channel
Restoring fish passage is great, but don’t forget about the habitat!
In natural environments, overhanging vegetation is important for shade, refuge and a food supply, but also helps fish migrate up along the edges of waterways.
This video shows a trial project funded by Nelson City Council, where PlanterPods and Flexi-baffles are working together to provide habitat and passage, along a section of heavily modified urban stream in New Zealand.
Fish Passage
Chuck Lobdell and the team at Johnson Creek Watershed OR have recently installed some flexible baffles in the culvert under Highway 26.
The aim is to improve fish passage in all flow particularly for spawning salmon.
The baffles are offset to provide a low-flow swim channel and also extend up the wall of the culvert to assist during higher flows.
