Tag Archives: rain garden

Talking while weaving

Even though the weather was turning cooler, I just got warmed up weaving the fence panels on our first rain garden cell in the parkway. Now that I had figured out the details and nuances, I was on a roll – or should I say loom?

And with each panel completed, our parkway landscape started to look better, even though I had nothing planted yet.

Community

We are always interested in community outreach, sharing with others what we are doing and why. We use this blog as a community outreach tool. We had several open houses where we invited the community to see our progress for themselves and ask us questions. I still accommodate groups that are interested in touring our project.

Despite all these efforts, we’ve had a hard time reaching the community closest to us, our neighbors in North Lawndale. Interest in and awareness of what we are doing to the house, and why, has grown over the years. But in the busy lives of our neighbors, and everyone’s daily struggle, the deep energy retrofit subject was not a priority. Plus, some of its aspects are rather abstract and eventually hidden behind drywall. There are few visuals that get people excited about, with the exception of our heating bill.

But once I started to work on the parkway rain gardens, interaction skyrocketed. I was doing stuff that was hard to overlook and that nobody expected to see in the neighborhood. Passers-by wanted to know what I was up to.

  

Interactions ranged from compliments on our work, to questions about what we were doing. Compliments and questions came from grown ups passing by and the kids leaving school down the street from us. A number of times, parents picking up their kids from school took them over to the parkway when I was working and asked me to explain to them what I was doing.

And of course, I mentioned the four brothers who helped me excavate the rain garden. We had some really good conversations, and they riddled me with questions until there was nothing left of me.

This was the fun part of putting the fence together, and I really enjoyed it!

Related posts:
Share

Parkway rain garden excavation

I had to excavate our parkway rain garden to a ponding depth of six inches. It was a very simple task, except for the treasure hunting aspect of our urban soils.

I didn’t want to start with the excavation until I had a barrier around the rain garden. Although the drop into the bottom of the rain garden wouldn’t be more than nine inches, I still was worried someone could fall into it. Now that I had a fence surrounding the parkway rain garden, with the exception of the fence panels, I was ready to start digging.

My goal was to plant my rain garden plants into a medium that resembles top soil. That was not an unrealistic goal, considering that the top layer in the parkway was a fairly good quality topsoil. But what was lurking underneath made things a lot more interesting. In a way, it was a little bit like archeological discovery that told a story corroborated by the surrounding landscape.

The parkway rain garden will stretch across two city lots. To the east is a vacant lot. It once had a building on it, but that was torn down. I am not quite sure when but it must have been sometime after the 60s. To the west is the lot on which sits our house, which was built in 1902. It think it is fair to assume to most buildings on our block were built around that time, including the house that once stood proudly on the vacant lot.

In my preparations for excavating I noticed that the parkway at the vacant lot had topsoil layer of about four inches, followed by a good six to eight inches of soil mixed with rubble. Below that was a decent layer of dark colored subsoil.

The parkway section in front of our house did not have the rubble layer. The topsoil slowly transitioned into an equally dark colored subsoil. It comes close to an uncontaminated or clean soil profile.

That may speak to the construction methods around 1900. I could assume that the crews cleaned up the site once they were done with the building, but I seriously doubt that. I think it is more likely that back in the day, builders didn’t use the equipment we have available today, and thus didn’t recklessly ruin the soils the way we do today.

The rubble layer at the vacant lot, on the other hand, most likely dates back to the tear down of the building.

Overall and given our urban environment we are blessed with decent soils, which we could maintain as long as I could find a way to address the rubble layer.

My method was as follows: I started by excavating and saving the topsoil, which is now in a stock pile in the vacant lot. Next I excavated the rubble layer and hauled it off site. Once I started excavating to the west, I relocated part of that topsoil to the east, until I had met my ponding depth of six inches.

A Tom Sawyer moment

When I started excavating, it was still summer break and the kids on the block were stifled by boredom, including four brothers who live two houses down. First they found some distraction by watching me dig. That lasted about ten minutes. Then they riddled me with questions. That lasted a little longer. Then they argued among each other who would do the best job digging. And finally they were begging me to help.

I got my spare shovel and let them have a try. To my surprise, the youngest and smallest of the four was not only the most skillful, but also the most relentless. He almost kept up with me. And once the last of his brothers had his turn, he wanted right back into the game – and I was grateful for the help!

Related posts:
Share

Parkway rain garden planning

Did I mention that I would like to convert our parkway into a rain garden? In case you haven’t read the previous posts, let me mention it again.

A rain garden is a shallow excavated and vegetated area that allows stormwater runoff to infiltrate into the ground. That begs the question: where will the stormwater for my parkway rain garden come from?

The contributing area

The adjacent concrete sidewalk will contribute some runoff, but not much, because the sidewalk surface area is actually smaller than the parkway rain garden.

The stormwater that I would really like to manage in the rain garden comes from the street and gutter. Surface drainage on our street is poor and we always end up with standing water in the gutter – sometimes for a couple of days, and sometimes for a couple of weeks. I would like to drain and infiltrate the street runoff into the parkway.

With that goal established, I could look at the appropriate rain garden depth and storage capacity. The elevation of our curb averaged around three inches above the gutter. The top of the curb roughly equaled the grade elevation in the parkway.

To manage the street runoff from the half of the street bordering the parkway (924 square feet), I should plan for a six inch ponding depth across the 470 square feet of rain garden. At a tested infiltration rate of two inches per hour, the parkway rain garden should be able to handle the 100 year design storm for the 924 square feet of contributing area.

The issue of conveyance

The next big question was, how do I get the runoff into the rain garden? I have a street curb that is in the way.

Typically one would rely on curb cuts to allow the water to flow from the street and gutter into the rain garden. But this is not my curb and I don’t want to get into trouble with the City. Whatever I do has to be easily reversible in case they end up not liking what I am doing.

I think I’ll start by drilling a number of one inch holes through the curb at the gutter low spots. Those holes can be easily filled and patched if needed. But because the holes only allow a limited amount of volume to flow through at any time, I may not be able to get all the runoff from intense downpours into the rain garden. So even though the rain garden could manage a 100 year design storm, the limited conveyance capacity may reduce that effectiveness.

I also will have the issue of maintenance. There is always a lot of debris in the gutter, which could clog the one inch holes. I will probably have to check on those holes a couple of times a month to keep them clear.

And I have two paths crossing the parkway, which leaves me with three rain garden cells. To connect these cells hydraulically, I incorporated PVC pipes under the path. This way runoff can easily flow from one rain garden cell into the other.

Related posts:
Share