Thoughts on Urban Streams after a Year of Playing in One

So it has been a year since I started mucking about and I have learned a great deal. I have spent uncounted hours (not a very scientific approach but this is art too) working on the site and learning what works and what doesn't where moving water is concerned.

From the very beginning I wanted to see what I could do with materials present on site and my own manpower-- no tools or heavy equipment-- just manipulation of the site itself with well-protected hands and feet. With climate change predictions of a 40% increase in rainfall in the northeast creating more intense storms, my efforts this past year are not proving to be very sustainable. The energies produced in summer storms are magnitudes greater than that of the base flow and silt in my vortex pools far too quickly. The good news there is that the pools stayed where I put them so I think I can take that as proof of their natural ability to resist and redirect flow into the vortex which is one of the premises that I started with.

Lessons Learned and Work for the Coming Year

The spiral jetty pictured on my page was something of a homage to the work of Robert Smithson. Unfortunately it was wiped out rather quickly during each summer storm and after several rebuilds I stopped doing it. If I were to attempt it again I would want to bring down some of the large granite blocks from the upstream end of the project area. When and if I have a volunteer force that can handle this I will try again as it was pleasing to the eye and I felt that it tied the site together nicely.

This year I will build deeper pools with raised central pipe openings. I will slant the horizontal pipe to provide a greater drop overall from opening to outfall. Hopefully, the faster flowing vortex will allow small particulates to travel through while the larger material will remain in the pool without blocking flow. Floating trash, leaves and branches will continue to plague the pipe opening but are easily removed.

I will use larger rocks from the upstream side of the project to define the pools and provide more pronounced spiral arms for excess flow and material to move out of the pools during storms. This will also help to stabilize the pools.

When the site is overwhelmed with storm water it produces a more laminar flow. I want to explore the idea of using twisted branches and vines on the sides of the stream to induce it to spiral horizontally as it travels downstream during storm events Schauberger diagrams of pipes and flumes show the use of battens to accomplish this horizontal vortex flow. I want to see what I can do with vines that I remove from the trees.

Over the last year I removed about half of the English ivy from the mature and undercanopy trees that surround the stream. I placed the vines across the stream which served as a net to collect leaf litter and debris as it came downstream. Debris dams like this provide much needed habitat for benthic macro invertebrates and can become microbial hotspots for denitrification and nutrient processing. They are a natural feature of forested unhindered streams. I will continue to crisscross the stream with vines so that debris dams form this autumn. I would like to see more of our city's leaves end up in our city streams but convincing Public Works that debris dams are a good thing is probably a hard sell. Doing it quietly at this site and documenting the results is what I can do for now.

The student from St. Timothy School planted yellowstem dogwoods and black willow in the floodplain area next to the stream this spring. I was surprised to find that several of the black willows had been pulled out leaving the hole that was initially dug as the only sign that they had been there. I believe that high water this autumn did this as I also found some plants where the soil was washed away from the roots but the plant was still there. For future plantings I will use rocks to help anchor them.

My attempts to reintroduce common bulrushes (a species that should be found at 90% of stream sites like mine in this region) failed miserably. Again, high laminar flow ripped them right out before they had any opportunity to establish themselves. I hope to plant more early this winter, focusing on areas where grasses and other non-native species have managed to hold on, even after the big storms came through.

I tried to remove trash as I worked but found the amount to be overwhelming. I disregarded it for a time and then started throwing it into the center of the stream making a trash spine so to speak. Each storm washed it away and redistributed it further downstream.

Trash is a big issue for people in Baltimore, one that we need to find better ways to address. As part of our St. Timothy School cleanup and planting project day, I had students make signs asking people to stop littering. I divided the students into three groups, one for pulling vines and removing trash from the park, one for planting trees and shrubs and the third group to stand out on the side of Northern Parkway- a very busy road, holding up the signs and waving at the passing cars. Students rotated through each job. The sign holders seemed to have the most fun. Many people honked in a friendly way. To further reinforce this effort I went back Sunday night and tied the signs to the fence by the road so that maybe, drivers on their way to work Monday morning would remember those waving, smiling students and think twice about any bad habits they may of had.

If anyone out there has read this far, thank you for your interest. Please look me up if you are in Baltimore. I would love to give you the tour. My e-mail address is dillond@ecostudies.org or you can leave me a message on my Bioneers page.

Namaste