posted 8 years ago
Hello Permies.
I am new here. I have designed a backyard swale, and I'm just not sure if it's a good idea. I seem to change my mind every 10 seconds. Perhaps you kind folks could lend some advice.
Here are the facts about my site:
1/4 acre suburban lot in Beacon, NY. Zone 6a
We get 49" of rain each year and 35" of snow each year, evenly throughout the year, except slight less in July and August. (Wetter climate than many swale systems are designed for, from my understanding.)
The backyard has just a slight grade. It drops about 1.5 to 2 feet over a 50 foot length. However, the neighbor's yard (uphill from the proposed swale) has a steeper grade and would likely contribute runoff into the swale.
Soil is quite compacted and slightly clay-ey.
I dug down about 4.5 feet to be sure I didn't hit the water table (on advice from Stefan Sobkowiak's permaculture orchard film). I didn't hit water. We've just melted a lot of snow over the last few weeks and the ground is not frozen, so I'd assume that this would be a high water table time (if it fluctuates). The sub soil seems very clay-ey.
I've got a nice chicken and annual bed rotation happening, which I really enjoy. Now I'd like to get some fruit trees planted and have read a lot about swales as tree growing systems.
The permanent nature of swales and trees has me a bit nervous about whether to do it or not.
The swale would collect over ground runoff. And I could rout some downspouts into it if necessary. I have room for a swale width of 2 to 3 feet, and a berm with of about the same. I want to plant fruit tree guilds on the berms.
The swale is about 50 -60 feet in length, on contour a squiggly "C" shape - I've already marked it in the yard.
I've attached a sketch of the plan. The blue is the swale. The brown is the berm. Orange (they scanned in light brown) are approximate one foot contour lines. Where it says vinyl fence is the highest point on my property, but the slope continues up in the yard where it says "N/F" in the bottom right of the page. Blue arrows show rain runoff directions. Overflow of the swale would head Northwest to the Asphalt Walk, between the house and garage toward the street. Very minimal grade through there - I'd almost say completely flat.
I've been on the property since August 2015 (not that long). So far, the only time of year it seems like keeping more water on the property is a good idea would be July and August. Yet, most every permaculture resource says the first thing we want to do is get our water harvest up. But this might be a case of "if it ain't broke, don't fix it."
Really the questions I have are, do I want to keep more water around if we get that much rainfall and snow each year? Will I end up with a swamp or trees with wet feet? Would this small swale make a difference?
I'd appreciate any advice you might have. I have browsed the Permies forums quite a bit, as well as searched the internet far and wide, but I haven't found a lot of info for anyone who has tried this in this wet of a climate. Point me to any relevant resources you know of. Thanks! Jesse
Filename: swale-plan.pdf
Description: swale sketch
File size:
591 Kbytes