Is the complicated part here mainly that putting something blocking fish might also lead to a backup in debris, in turn stopping water flow? Or is it that whatever's blocking fish flow can wear...
Is the complicated part here mainly that putting something blocking fish might also lead to a backup in debris, in turn stopping water flow? Or is it that whatever's blocking fish flow can wear away if the ground it's connected to wears away? Both? Wasn't completely clear to me from the article
Mark Eisenman, a former fisheries biologist who now works as a planner with Alaska’s transportation department, called the grant funding critical because many of the culverts below the long Parks Highway are clogged with debris — blocking the channels for fish while heightening the threat of catastrophic flooding.
Eisenman said some of the Alaska culverts under the grant would be upgraded to steel plate aluminum and anchored with gravel and rocks to make sure the barriers aren’t too high — or that the water doesn’t flow too quickly — for salmon to be able to pass through. end quote
Is the complicated part here mainly that putting something blocking fish might also lead to a backup in debris, in turn stopping water flow? Or is it that whatever's blocking fish flow can wear away if the ground it's connected to wears away? Both? Wasn't completely clear to me from the article
I found this which should help. https://www.fisheries.noaa.gov/west-coast/endangered-species-conservation/fish-passage-solutions-west-coast-culverts-tidegates-and#:~:text=The%20downstream%20end%20of%20the,passage%2C%20but%20water%20as%20well.
Also, these paragraphs seem relevant.
Mark Eisenman, a former fisheries biologist who now works as a planner with Alaska’s transportation department, called the grant funding critical because many of the culverts below the long Parks Highway are clogged with debris — blocking the channels for fish while heightening the threat of catastrophic flooding.
Eisenman said some of the Alaska culverts under the grant would be upgraded to steel plate aluminum and anchored with gravel and rocks to make sure the barriers aren’t too high — or that the water doesn’t flow too quickly — for salmon to be able to pass through. end quote
Ah that makes sense now, thank you for that!