We became aware a meeting was held on 02/08 for three Councilmembers where our Ballard Roadside Raingardens were discussed. See the meeting here: SPU and Neighborhoods Committee Meeting (the Ballard Roadside Raingardens are discussed between 44:00 and 66:00).
Since we were unaware of the meeting and not invited to present our issues, we sent the following response to Councilmember Mike O’Brien and the two other Councilmembers present:
Dear Councilmember O’Brien:
Many members of the Ballard Green Streets Initiative pilot project had the opportunity to watch a recording of the Seattle Public Utilities (SPU) and Neighborhoods Committee meeting held on February 8, 2011. Given we were unaware of the committee meeting and therefore did not have an opportunity to submit our own report, we would now like to submit a few points surrounding our Ballard Raingardens pilot project:
- A critical clarification to the answer given to Councilperson Harrell’s question asking whether the properly functioning Raingardens would drain after 72 hours (SPU’s Trish Rhay’s response was yes): Per current design criteria, a properly functioning Raingarden would drain within 72 hours after the rain has stopped, which is a significant detail in the Seattle area. Using the 2010 rainfall data as a sample, this design executes as only five “dry Raingarden” days in January through April of that year. In a properly functioning Raingarden, there would still be standing water for the majority of time during winter months. In addition, it concerns us that a significant amount of literature in the raingarden/bio-retention field indicates that Best Management Practices (BMPs) for raingardens/bio-retention ponds is for drainage within 24 to 42 hours after a significant rain event. We are still curious why these bio-retention ponds were apparently designed for 72 hours after any rain event.
- To this point, in the slide entitled Ballard Roadside Raingardens Pilot Project Community Feedback & Report Out, which stated the community concerns, one of the key items omitted is our concern regarding the design: We do not feel that standing water in a depressed area until 72 hours after rain has stopped in Seattle is an appropriate design for an urban neighborhood with children and elderly residents.
- The Performance Monitoring Summary slide displayed a sample of only one block and indicated that most cells are performing to design standards. This is not representative of our block and intersection. In our area, only 32% of the cells are draining well; 68% are draining poorly or not draining at all.
- Furthermore, and more significantly, the curb inlets to these cells have been blocked with sandbags or asphalt plugs since construction, so the drainage data should be considered inconclusive until those cells are operating as intended.
- Additionally, the cells that are not draining at all are actually filling up after being pumped, even when it is not raining, indicating these are below the water table and cannot possibly serve the function for which they were built. Furthermore, those curb inlets have been opened up so excess water can drain into the rainwater sewer. This in fact exacerbates the problem, since groundwater that would normally remain in the ground is now being drawn out and poured into the rainwater sewer during overflow from a rainstorm.
- The presentation stated, “Ballard offers a unique opportunity for green solutions.” We disagree due to the Vashon Glacial Till (clay) covering 17 feet (after the top soil) of Sunset Hill. (SPU’s Andrew Lee acknowledged, “These are definitely some special soil conditions that we’re encountering here that are different from our previous projects.”) This is probably the reason our storm drains were connected to the sewer lines during Ballard’s infrastructure construction long ago. Now the bio-retention ponds are collecting water that is essentially sitting in clay bowls. The perc and soil tests should have revealed this, but on our two blocks, only two sites were tested during the drier summer months. In fact, it now appears the perc tests may have revealed that the location of these bio-retention ponds would not be advisable under BMPs.
- In conclusion, the name of this pilot project should be changed from “Raingardens” to reflect a more accurate term. By definition, the ponds as constructed per the existing design are not raingardens and therefore should not formally be referred to as such. Instead, they are bio-retention ponds. In fact, during this 2/8/11 committee meeting, Andrew Lee stated the raingardens are being transformed into a “detention raingarden,” which in essence acts similar to an open cistern. A “detention raingarden” is really an anomaly, since true raingardens drain within 24 hours, so the project should be adjusted for true identification and possible location adjustment given the functionality (i.e. we feel there should not be open cisterns located in planting strips of an urban neighborhood street).
What one may call a learning experience, others may call an acute lack of planning and awareness, particularly when dealing with such substantial endeavors as neighborhood alterations. To be clear, the foremost issue now is that valuable and extensive funds have been spent to resolve the Combined Sewer Overflow (CSO) issue that we all know to exist, and these bio-retention ponds are clearly not addressing that CSO issue. Sadly, our neighborhood has been flagrantly devalued because of this pilot project that was commenced without studying the data beforehand. We still support and understand the green option of Raingardens; we would like to see them all function within BMPs for a single-family neighborhood and to be more appropriately integrated into the community.
We have signed up to participate in the Task Force and look forward to working with SPU toward promptly achieving our goals. Despite communicating with SPU over an eight-month period—via emails, a blog (www.ballardraingardengue.wordpress.com), and feedback in community meetings—we have not seen any modifications in project implementation that reflect results adequately addressing our concerns.
We would like to be invited to all future committee meetings that address the Ballard CSO pilot project, particularly since time is allotted for community participation. It is important to us that we are able to continue to publicly express our concerns and work cooperatively to resolve the issues to reasonable satisfaction.
Thank you for taking the time to consider our perspective. Please contact me if you have any questions or would like more information from the perspective of the residents on 77th and 29th/28th Avenues Northwest.