Once again, SPU plans to install raingardens to limit stormwater flooding our sewer system during storm events. To jog memories, these were the “cesspools” called “The Worst of Seattle 2011” by Seattle Magazine: http://www.seattlepi.com/lifestyle/article/The-worst-of-2011-in-Seattle-2431517.php
SPU has promised they have learned lessons and improved the plans. But there are still disturbing issues with SPU’s new proposals. Primarily, enormous sums of taxpayer dollars will be spent for very little reduction of stormwater flowing into the combined sewer system. It seems SPU wants to return to Ballard to prove they can install raingardens correctly (and not make 2014’s Worst of Seattle list) rather than achieve any real impact.
They say:
Twenty raingardens will divert 100,000 gallons of water.
Response:
Since the overflow is 60 million gallons, twenty raingardens equates to less than 2% of overall stormwater savings. The result is minimal when held up against the community’s valid concerns.
The last set of raingardens ran up a price tag of $2.5 million (some of that in a loan we’re still paying off): Let’s save that money and invest in the underground water storage, since North Ballard is not set up geologically for this sort of solution due to the hard-pan soil (glacial till).
They say:
They have performed testing to find the right soil conditions.
Response:
North Ballard is made up of layers of different soils, the most prominent being hard-pan (glacial till), which is like clay. Add in cross-sections of sand, hidden streams, and deceiving small pockets of absorbent soils, and the difficulty increases in locating the right environment here to install a functioning raingarden. We saw in Broadview (as one example) how introductions of man-made waterways caused unforeseen natural adjustments and flooded basements.
The risk is great; the return is small.
They say:
Lessons learned from last time: (1) Take your time, (2) Do your homework, and (3) Listen to the community.
Response:
There was enough time in Phase I to perform testing; testing will not always show the later problems (see above). Also, the community would not need to be involved (or spend this much time getting involved) if these raingardens demonstrated safety, worked effectively, and didn’t waste money.
They say:
The raingardens will have a slope, running water during rain events, and will drain two days after a major rain event.
Response:
Read from our experience: These raingardens will drain two days after the rain stops (an important detail). A typical rainy March in Seattle could mean running and pooling water the entire time.
Tracy Tackett, program manager for SPU’s Green Stormwater Infrastructure, is quoted in Sightline Daily: “If people won’t tolerate any ponding ever in the rain gardens, it won’t work.”
They say:
These raingardens look better when vegetation grows in.
Response:
Vegetation can also hide the slope and pooling water, which is more dangerous for children, elderly, and disabled residents.
They say:
The exact locations of the raingardens have not been determined as of yet.
Response:
Open cisterns with running and standing water should not be close to a school or community center, or for that matter, in an urban neighborhood unexpectedly off the sidewalk.
What they didn’t say:
Raingardens of identical design in Redmond, Washington, are showing very disturbing outcomes: Copper, phosphorus, and other toxics are infiltrating out of the raingardens at a rate greater than flowing in. In other words, toxics from the raingardens are infiltrating into groundwater. The Washington State Department of Ecology, a strong advocate of raingardens, has expressed concern and advised slowing down raingarden installation until the cause of toxic infiltration is determined.
Response:
Find a better solution.
The Ballard Raingardengue 