Seattle Public Utilities is planning a significant increase of new “roadside raingardens.” The current proposed locations are here, including next to Loyal Heights Elementary and Loyal Heights Community Center/playfield.
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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.
Twenty raingardens will divert 100,000 gallons of water.
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 have performed testing to find the right soil conditions.
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.
Lessons learned from last time: (1) Take your time, (2) Do your homework, and (3) Listen to the community.
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.
The raingardens will have a slope, running water during rain events, and will drain two days after a major rain event.
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.”
These raingardens look better when vegetation grows in.
Vegetation can also hide the slope and pooling water, which is more dangerous for children, elderly, and disabled residents.
The exact locations of the raingardens have not been determined as of yet.
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.
Find a better solution.
New “raingardens,” now dubbed “Ballard Natural Drainage,” are returning to Ballard in 2014-2015. According to local mailers, SPU is honing in on blocks surrounding Loyal Heights Elementary and Loyal Heights Community Center.
SPU will host a Community Meeting to discuss this project on June 5th at Northminster Presbyterian Church (7706 25th Ave NW) starting at 6:00 PM.
Stay tuned to this blog for more information.
We applaud SPU’s decision to begin removing some of the ineffective Raingardens, which include the ones on 77th and 29th. After determining these specific Raingardens are not solutions for the Combined Sewage Overflow (CSO) issue, SPU will be refocusing its efforts on other opportunities that can produce measurable results.
This blog aims to continue the conversation surrounding those other solutions. Please see our “Options” tab and feel free to contribute to the list.
Our Ballard Raingarden Project has been profiled in Crosscut. The article summarizes well some of our issues and emphasizes we would like to see green solutions that are effective in cutting back the Combined Sewage Overflow (CSO).
As discussed in the KIRO news story, SPU is now meeting to decide on the individual Raingarden’s statuses moving forward.
The residents on 77th and 29th have notified SPU they want all Raingardens on their blocks and intersection removed due to lack of infiltration and resulting safety hazards and ineffectual results.
The story profiled the lack of drainage in Ballard’s soil conditions, and the safety concerns this raises.
Found in Montana’s books:
Mont. Code Ann. §7-31-4201 et. Seq.
“The legislature declares that the control of ditchwater in inhabited areas of Montana is affected with the public interest. The purpose of this part is to prevent drowning of children in ditches filled or partially filled with water within the limits of an incorporated city or town.”
Children really do drown in ditches filled or partially filled with water.
As the ponding continues and the Combined Sewer Overflow (CSO) issue is not being resolved, the residents on 77th and 29th Avenues have contacted outside experts for more analysis.
We have been working with a hydrologist at Shelterwood Consulting, who graciously offered to present to SPU and the Task Force at our last meeting. The presentation can be found here: http://www.shelterwoodconsulting.com/Ballard_Bioretention_ponds.html
In summary, the consultant confirmed and emphasized these ponds were installed on top of Vashon Glacial Till (clay or hardpan), and therefore the water does not “perc” (or infiltrate) through this layer once it is saturated. The perc and soil tests performed by SPU indeed revealed the native soils would not be appropriate for infiltration-based bio-retention ponds. Additionally, these tests were conducted during the middle of the summer when soil is dry. SPU also neglected to add a “correction factor” to the test results, which would have shown even worse perc rates. Best Management Practices (BMPs) advise against installing bio-retention ponds with the type of soil and perc test results found in most of this pilot project area.
Additionally, although it cannot be confirmed without more testing, we believe the perch water (or groundwater) could possibly be drained as well if underground drainage were installed, exacerbating the CSO issue.
As a result of the consultant’s analysis and our extensive monitoring since implementation, we on 77th and 29th have changed our viewpoint:
Since these bio-retention ponds are not a viable Combined Sewer Overflow (CSO) solution, we would like to see this pilot project stopped, the ponds removed, the parking strips returned to their original state, and other CSO solutions sought.
Please see our updated issues on the Issues tab, and find our suggested alternative solutions on the new Options tab. Additional suggestions are welcome and will be added to the list.
Bugs have begun hatching in and emerging out of the Raingardens.
From a neighbor yesterday:
“There are a gazillion….gross brown flies the color of sand that are crawling around the fetid standing water of the cell on the North Side of NW 77th nearest to the alley. I find them to be really gross.”
Another neighbor sent pictures from today: