Under water grasses
What grasses do you suggest to grow near the river bottom .The area is covered by water all Winter . The grasses growing there now grow 3 to 4' tall ,And seem to hold the soil well
Marion County Oregon
There are a few references that I suggest to people in this situation. These will give you some ideas and help you shop for them, or related plants, at a nursery.
These references are research-based and been reviewed by many horticulture experts, even though they are not university publications.
Please be careful to not purchase an invasive plant. Many nurseries sell invasive plants for controlled garden environments that would cause significant damage if planted along the streambank. A common example is butterfly bush.
You may also already have a problem with reed canary grass. It is invasive and already exists along many streams throughout Oregon. It is extremely difficult to remove. The good news is that it works well for erosion control, but it takes over and makes it difficult for native plants to become established that would provide more ecological benefits. If this is the case for your situation, I suggest focusing on removal and getting native vegetation established in a few areas at a time rather than trying to tackle the whole problem at once.
Let me know if you need more references or would like to talk with someone. There are folks at OSU that are far more experienced than me in dealing with these situations. You may also want to contact the Marion Soil and Water Conservation District. They have some folks that help people with these projects on a regular basis. https://www.marionswcd.net/.