Earthworks for drainage ditch

Hello everyone, i have a ditch running along my northern property line that is about 150 Feet in lenth. Its full sun. It is the lowest elevation on my land. Water comes in at the NE corner and flows out at the NW corner.

This ditch runs in front of a few houses so it consists of road runoff, toxic lawn gick runoff, and general poisen spray. My neighbors, including right nextdoor to me are lawn people. Spray it, scalp it, water it, repeat. Its really troubling for me to see someone scalp a bermuda lawn when its 100F outside so its basically brown and dying, then water it all day in the heat of the sun with a sprinkler. Ughhh.. Anyway i digress.

Some folks up the ditch have paved the bottom with concrete, some folks put in a buried pipe and grew grass over the ditch. I have noticed up on the concrete that the water has left crusty white and pink stains, very toxic seeming.

So the area is essencially toxic, and has powerlines running overhead so it also has an electromagnetic field on it. My ditch is about 5 feet wide and 1-2 feet deep. And is covered with some type of grass. I had the idea to do ornamental bananas and taro, that would totally shade the ditch. I went to the asian market and picked up taro bulbs and stuck them in the muddy rocky center of the ditch. Success! Two plants sprouted and have grown up through the hottest part of our season. When water flows it pushes them over, but the grass kind of supported them too.

So my plan is evolving and i plan to dig some of the sediment out of the ditch since it appears to be about 1/4 of the way filled in from what it once was.

How would i go about forming settling lagoons, small dams, and other things to make the area better. As it is, water is in there even a day or two after rain, so if i had a small dam then more water would remain after the rains. Problem is this ditch handles a lot of water and will flood into the street if i cause it to overflow. For some reason my mind is thinking wooden dams that Could be installed in such a way that the shallow flow hits the wood but its short enough that when the ditch fills up water can flow over the top. Anyone have experience with anything like this?
My dream for the area would be a vernal pool or frog pond type thing covered in lovely taro leaves with bananas poking out.

I would love to see a picture of the ditch. Do you want to expand certain parts of it to make a pool, or just dam it to hold water longer? Can you divert any of it to a separate pool?

The two photos show the two sections of ditch, which are interrupted in the middle by my driveway.

And a shot of the zero care taro.


My very first thinking before moving in was that i would divert the water early on the ne corner and bring it up to some plantings in front of the house, but now that i am actually here observing it seems the slope of the ground as you travel south away from the ditch is steeper than it appears. As in, to divert the water it would have to travel up hill quite a bit. The other issue is the possible contamination at that point is the highest since its new water entering the property.

One distinct possibility that will maybe be hard to understand without a full drawing, is my idea to eventually have a third or forth pond in the north west quadrant of the land which could overflow into a wetland type area connected to the First ditch you see above.Since that pond would be the 3rd or 4th in sequence the water would be the cleanest.

If i planned on that then the entire east section of the ditch could be designed to slow and filter the water as much as can be, as you can see i already catch a lot of grass and floating debris with the long grass. The west section would then in theory be slightly cleaner, if it was fed from two places then it would also be wetter for longer.