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In the article, he discusses putting in French drains. If berming into a hillside, having French drains that are lower than the sunken green house would do the

In the article, he discusses putting in French drains. If berming into a hillside, having French drains that are lower than the sunken green house would do the trick. You could have two symmetric drains that start on the middle of the back (north) berm, follow around the side walls, and then drain out on either end below the low/south wall. https://en.m.wikipedia.org/wiki/French_drain https://en.m.wikipedia.org/wiki/French_drain

metadat 4y ago
French drains are good for normal amounts of moisture, but once you're talking about a structure installed at a low point and receive an inch or two of rain in less than 24 hours, the drains and ground will be saturated and then you're gonna have a bad time. I'm only thinking of this because of the extreme amount of rain we've been having in the Bay Area this past week. Normally it wouldn't be a big concern.
- jonstewart 4y ago
  I mean, siting is everything. I’d only build one of these in a hill. I’ve got an earth-bermed house in a hillside in rural Wisconsin. There were terrible floods in the area in 2018, but the drains around the house sent all the water down the hill to the creek.
- hosh 4y ago
  From what I remember, the Bay Area doesn’t have enough porous layers to absorb water. It’s rocky ground and bedrock. You don’t need to put the sunken greenhouse at the lowest point. Layer some berms below the greenhouse on the slope — effectively form swales — and plant some things there. Another possible solution is to dig out a cistern. Here is an example from India, where much of the water is concentrated in monsoon storms. Even with such heavy rain, there are cities suffering from drought. https://youtu.be/AvV-L8MdhO4 https://youtu.be/AvV-L8MdhO4 They have two storage tanks, and the excess goes into the onsite well to recharge ground water, instead of washing into the streets, contributing to flood conditions.
  - metadat 4y ago
    Yes, the Bay Area is mostly hard packed clay.
    - hosh 4y ago
      On the other hand San Francisco’s hardiness zone is 10a, 10b. If there is enough sun, it can support zone 10 tropical plants without a greenhouse, sunken or otherwise.

metadat 4y ago

French drains are good for normal amounts of moisture, but once you're talking about a structure installed at a low point and receive an inch or two of rain in less than 24 hours, the drains and ground will be saturated and then you're gonna have a bad time. I'm only thinking of this because of the extreme amount of rain we've been having in the Bay Area this past week. Normally it wouldn't be a big concern.

jonstewart 4y ago
I mean, siting is everything. I’d only build one of these in a hill. I’ve got an earth-bermed house in a hillside in rural Wisconsin. There were terrible floods in the area in 2018, but the drains around the house sent all the water down the hill to the creek.
hosh 4y ago
From what I remember, the Bay Area doesn’t have enough porous layers to absorb water. It’s rocky ground and bedrock. You don’t need to put the sunken greenhouse at the lowest point. Layer some berms below the greenhouse on the slope — effectively form swales — and plant some things there. Another possible solution is to dig out a cistern. Here is an example from India, where much of the water is concentrated in monsoon storms. Even with such heavy rain, there are cities suffering from drought. https://youtu.be/AvV-L8MdhO4 https://youtu.be/AvV-L8MdhO4 They have two storage tanks, and the excess goes into the onsite well to recharge ground water, instead of washing into the streets, contributing to flood conditions.
- metadat 4y ago
  Yes, the Bay Area is mostly hard packed clay.
  - hosh 4y ago
    On the other hand San Francisco’s hardiness zone is 10a, 10b. If there is enough sun, it can support zone 10 tropical plants without a greenhouse, sunken or otherwise.