Rain Water, Driveways and Dry Wells

Many buyers have “must haves” on their list of criteria for a home. For many, especially in urban neighborhoods, that includes off street parking. 2356 NW had no off street parking but now it does. Our permit to put the driveway in did not mention storm water management; it is under the minimum square footage that requires a runoff plan. What wasn’t considered, by either us or the planning office, was the roof runoff that was previously being piped onto the sidewalk by an underground pipe where the driveway was dug. Quick call to the City left two options, “install a dry well or connect to the sewer.” Connecting to the sewer means cutting up the street since the house connection is at the top of the property. The dry well became the better option. With the right tools for the job already on-site, the nine foot hole was dug in the driveway (we made it all the way through the clay to sand), backfilled with some gravel and three concrete rings stacked on top of each other, capped and surrounded by gravel. The added benefit of the dry well is that we will be able to collect 100% of the runoff from the property, not just the driveway and single downspout.






4 Comments on “Rain Water, Driveways and Dry Wells

  1. Thanks for posting this. It’s really interesting.

  2. Connect storm water to the SEWER? What idiot gave that advise? Storm water should never be connected to the sewer line unless soil stability requires it, and only then until a separate storm water system can be constructed.

    The City of Portland is having to invest umpteen millions to decrease the % of storm water in the sewer system to decrease the # of overflows into the Wmt & Columbia.

  3. Where did you find a concrete drywell that size in the Portland area?

  4. The drywell is three, maybe four, pieces that stack on top of each other.

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