Designs, Tricks, and Schemes

Stormwater Management at its Most Beautiful


Ed Snodgrass stands on stage 1 – the green roof.

Ed Snodgrass is the internationally known green-roof author, consultant and grower whose own Maryland nursery experienced downpours gushing downhill, unstopped by mere turfgrass. Of course he was using vegetated roofs, but that wasn’t enough.

As Ed wrote me, “Even though the farm is mostly pervious, in high intensity events water used to stream down my driveway. Now that is mostly managed completely, except for the largest storms and then it is moderated.” He doesn’t even mention how stunning the solution looks, but then he’s a modest guy.


Stage 2 – the upstream pond and plantings.

To solve the lingering problem he replaced those patches of lawn with three gorgeous gardens that in sequence create what’s called a treatment train. He explains that “Any one of the systems might get overwhelmed but working together, they each help the other. The green roof slows the water down, allowing the water to be eased into the system at a slower peak rate.”


Stage 3 island bed with pond.

And “The two small ponds are for detention and infiltration.” Well, the ponds may be small ponds but they’re surrounded by hundreds of water-retaining plants.

Stage 3, shown above and below, was designed by Australian designer Mel Ogden, whom Ed met while working on a project together in China.

Mel chose the disease-resistant Rudbeckia deamii as the showstopper for the garden. Massing is her style and wow, I’m all for it.


Stage 4 uses grasses and “meanders.”

The caboose in Ed’s treatment train, also designed by Mel Ogden and installed just a year ago, is shown above and below. He explains that it as “uses the meanders for sediment deposit and slowing the velocity of the water.”


Here’s Ed’s approach from his decades in the trenches of stormwater management: “All of that is pretty standard stormwater stuff. We are just trying to show they can be gardens and not just ditches and sediment ponds.” (Hear, hear!)


Early May 2015

Ed sent me these photos of the design and implementation phases, with overhead views from a second-story window being especially instructive.

June 1 2015 front bed

June 1, 2015


July 2016.


I recently visited Ed, curious to see all this and frankly seeking some hippie companionship. I thank him for that (he has stories!) and for his photos, especially this last one with rain flowing through it, taken this week. Just a year old, the treatment train caboose is performing as intended and is beautiful already.

Ed with plant list for stage 2 garden.

Ed with plant list for stage 2 garden. Photo by Allen Bush.

To learn more, read Allen Bush’s 2015 post about Ed’s garden. 

Plants selected by Mel Ogden for the newest garden are: Sesleria autumnalis, Sesleria caerulea, Panicum virgatum ‘Kurt Bluemel, Pennisetum viridesenes, Sporobolus heterolepis, Carex humilis ‘Hexe,’ Carex pensylvanica, Carex testacea, Calamagrostis brachytricha, Deschampsia flexuosa, Stipa gigantia, Bouteloua curtipendula, Phedimus takesimensis, Acer palmatum Shishigashira, Acer palmatum Bloodgood. 

Posted by on August 19, 2016 at 10:26 am, in the category Designs, Tricks, and Schemes.
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10 responses to “Stormwater Management at its Most Beautiful”

  1. PermieWriter says:

    These principles definitely work for smaller spaces!

    We moved onto our 1/12 acre place in 2010 – almost no elevation changes on the place, but we’re just slightly uphill of our neighbors, so when the rains came, the runoff from our place would swamp theirs.

    We dug two deep trenches and smaller ones leading up to it – then covered it all in inches of wood chips. The yard looks and feels flat, but you can tell the difference when it storms.

  2. Ed Snodgrass says:

    Hi Anne,
    The water leaves the final stage of the treatment train across a section of lawn then through a narrow tree buffer zone and into a small stream. That is if there is sufficient water to make it all the way through all phases of treatment.

  3. Linda Andrews says:

    These are beautiful. I am wondering if Ed Snodgrass could share some of his construction techniques for building rain gardens. Does he recommend using native soils only, replacing soils with sandy/composty soil mixes or adding compost to the top layer? Does it depend on the quality of the existing soils? Does he use gravel under drains ever? I am curious about regional differences in rain garden construction. The formukas are similar but different from jurisdiction to jurisdiction. Thank you!


  4. anne says:

    What happens to the water at the end of the caboose? Does it get drained into a culvert under the road, or allowed to run over it?

  5. Gorgeous! I love to see places that combine beauty and function like this. What a great example of how we can creatively solve multiple problems. Thanks for this post.

  6. John says:

    Very cool. I don’t have the same amount of space but I think there are still some principles that I can use to slow down and absorb more rain water in my small garden.

  7. […] Stormwater Management at its Most Beautiful originally appeared on Garden Rant on August 19, 2016. […]

  8. tanya says:

    I wondered about that, too. It’s the “barn,” and you can see it way over to the left in the photo at the end of this article:

  9. Carolyn says:

    What is under the green roof? It appears to be growing on the ground.