Low impact development near the Navy Yard

Near the soon to be opened and fantastic Park at the Yards, there’s a lot of new low-impact development infrastructure.  These bioretention areas should be a great example of the new kind of both urban and environmentally sustainable infrastructure can be.


These are not ordinary tree boxes.  Instead of draining into a standard storm sewer, these gutters drain into the tree boxes, where stormwater then naturally drains into the ground instead of into a storm sewer.  This reduces the amount of water entering the combined storm and sanitary sewer, and thus can help reduce the number of combined sewer overflow (CSO) events.  Since the combined sewer system mixes storm water and regular sewage, substantial rainfall will force the system to overflow into area rivers, dumping raw sewage mixed with stormwater directly into the Anacostia and Potomac.

From the street side:


Storm water will slowly absorb into the ground, aided by the various plants soils that can capture pollutants though the process of biofiltration.  Look at other rain gardens and tree boxes under construction – note the drainage layers of soil and gravel to be added.



In this completed rain garden/tree box, note the grade of the soil in the box, below the grade of the curb:


Cross-posted at Greater Greater Washington

8 comments to Low impact development near the Navy Yard

  • This is great to see! I cant wait to get down to take some site photos of bio-retention cells at work. Does anyone know who was involved with this project, this is the first I have heard of the LID approaches down there.

  • Alex Block

    Doug, I don’t know if this is part of the Yards Park development, or if it’s something that the master developer is doing as part of the larger infrastructural improvements around the area.

    If Hurricane Earl tracks close enough to us, we might get some serious rain to test these out…

  • re

    Kudos on “trying” to remedy the runoff issue, but complete and utter failure in terms of execution.

    Here is why:

    1. Those boxes are structurally reinforced, CIP concrete structures. Combined with the proper cross section of soils and gravels, they cost an absolute fortune. Those two seperate boxes, in materials and construction alone cost somewhere in the neighborhood of 25-30K a piece…for a tree box.

    Not only that, but they completely fly in the face of so called “dense” urban planning. Those enormous boxes require larger than required setbacks, which then pushes the sidewalk ROW back, which then pushes the building limit line back.

    So this has resulted in a lower density use of the land.

    The District is requiring these as a part of their development proffering, but what they should really be doing is simply collecting the money that would have been spent, and putting it toward the 2 billion dollar storm sewer tunneling “exercise” and wate rtreatment plant renovations DC Water is planning.

    Complete and utter waste of land, money and effort.

  • These look fantastic. I attempted something similar to this in downtown Pueblo, CO with the cuts in the curb of the street. My attempt utilzed tree grates to minimize the need for the railings. This looks great. Thank you for sharing this! -John

  • A higher density is not always the solution to an urban environment, plenty of studies have shown that street life is comprised of many factors not just density, not to mention the reduction in the heat island effect, air quality, energy savings, climatic incentives and aesthetic and community benefits that these type of Low Impact Development (LID) systems provide. These systems are the beginning of decentralized storm water controls and overall pollutant reduction into the Anacostia and Potomac rivers. I think the generalization that these are cost ineffective is preposterous and don’t looking into the larger picture of what a reduced CSO would provide to the district and the Chesapeake Bay Watershed. If you think that a multi billion dollar storm water sewer renovation is going to solve the problem you are mistaken. Over 2/3rds of The District wont even see an improvement with the new system and still leaves over 100 million gallons of overflow into local water systems. These systems can be implemented today and actively reduce pollutant and storm water from entering the current system.

  • Alex Block

    I don’t buy the argument that these kinds of structures reduce the potential development density of a site. They’re not any bigger than standard tree boxes you’d find on just about any sidewalk in the District.

    Dense development is a good thing, but it doesn’t mean you can neglect the public realm or push for bad streetscapes. You’d want this kind of a buffer zone anyway. For the picture I took of the largest tree box/rain garden, I’d note that there’s a large curb bump-out.

    Framing this as an either/or decision with regard to built density is a false choice.

  • To clarify on my first point, it refers to the supposed lost density that these features bring. Dense development is, as Alex describes, a good thing…

  • The tree boxes really helps in so many ways.This reduces the amount of water entering the combined storm and sanitary sewer, and thus can help reduce the number of combined sewer overflow events.

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