Restoring rivers and floodplains

Slowing water in the landscape by using techniques like swales and improving soil organic content can get rivers to flow year round again, because water moves more slowly underground so it can come out during the dry months.
Allowing rivers to overflow into floodplains helps aquifers fill up.
See more at https://climatewaterproject.substack.com/p/on-rivers-floodplains-vegetation

I just want to pick your thoughts here.  My understanding is that flood control is best accomplished by slowing water starting from the very top of a watershed.  This is so that water gets slowed down before it ever picks up any speed, delaying water shedding down the gradient and hopefully keeping soil in place.

This doesn’t mean that one shouldn’t make swales, etc. if one only has lower lands, just that it is best to slow that water as soon as possible.

Eric

The forms of slowing water that I am most familiar with are brush dams, rock dams and check dams.

Are these mentioned in the video?

In working on a river, and then living upon another one, I do know a river system is very complex, but it seems here anyway, we already do what is proposed.

As an example, the river I live on is seventy miles long, yet starts at 255 feet in elevation and ends at 52 feet in elevation, or 200 feet roughly of drop in 75 miles. Along that length there is (3) hydro electric dams producing about 6 megawatts of power. That is not very much, but its like that because it is very gradual, meaning there is a LOT of wetland and swamp it is filling. In fact, the middle dam is required by FERC to send 250 cubic feet per second into one particular wetland to ensure it stays wet year around.

But river systems are really complex, because they must balance out a lot of needs. There is hydro electrical generation, which is a very good use of rivers, not just renewable energy in usable quantities, but power produced 24 hours a day and not just during the day or when the wind blows. They can also be run-of-river or peaking facilities, and of course can black start the grid.

But there are other uses too, like industry. The head pond where I work feeds a paper mill that employs 1200 workers, and with a new paper machine being installed: soon 1500 people. That is a lot of good paying jobs in this area, but they need water in which to make paper.

These same head ponds also create man made lakes, and surrounding them is expensive property, property where homeowner spend a LOT of money on property taxes. These help everyone in town have a better functioning municipality with police, fire and ambulance services benefiting more than just the shore owners. But in some instances like mine, where I live on a bend in the river, the dam two miles upstream of me also protects my home from flooding.

But then too there is sportsmen. People love to fish, and so access for that is important, whether getting fish upstream with fish lifts, or downstream. But one thing people often forget about is what happens when there are no means to keep out invasive fish. Dams can stop that evasive fish migration while yet letting native fish pass upstream with a fish lift. They are not exactly cheap, the one by me cost 19 MILLION dollars.

The point of all this is; rivers are very complex, and when you mess with one thing to get one result, you get a lot of problems you did not expect to get in other areas. For this reason FERC is VERY VERY adamant about maintaining a level of a head pond. It is within 2 feet (plus or minus) of a set elevation. Every week calculations are made on snowpack levels and predicted rain fall so that the head ponds neither get to high, or too low. It is a very delicate balancing act because so many things depend on those water levels being exactly where they are, from fish, to landowners, to white river rafting, to mills having water to make product, and in making electricity. It is a tough balancing act for sure. I know, rivers are my life in working them, but also living upon one.

Eric Hanson wrote:  My understanding is that flood control is best accomplished by slowing water starting from the very top of a watershed.  This is so that water gets slowed down before it ever picks up any speed, delaying water shedding down the gradient and hopefully keeping soil in place.

Reading I've done recently, suggests that one of the best ways to accomplish this is by reintroducing beaver. They not only slow the water, but they prevent streams from cutting out their beds, and create meadow habitat that is beneficial to many other plants and animals.

However, artificial wetlands can be constructed at sewage outflows in an effort to harvest the nitrogen, potassium and other nutrients in the sewage. Sewage treatment is  mostly aimed a killing nasty bacteria and viruses, not removing nutrients. Those nutrients in turn, damage rivers through algae blooms etc.

Similarly, building artificial wetlands at places where run-off from farmers fields and urban storm-water outflow is likely to happen, can again, make use of those nutrients before they cause trouble in rivers, and even the ocean.

What’s FERC???

Gaurī Rasp wrote:What’s FERC???

Federal Energy Regulatory Commission (USA)

There's an organisation called Mossy Earth, the do all kinds of 'rewilding nature' projects, including restoring rivers. Most projects in the UK, but they work in other countries too. You can become a member, donate, work as a volunteer ... or only watch and like their youtube channel (that's what I do): MossyEarth