This piece was written in 2009 and republished 720/2012 for your interest. Details to follow here on it's slated development on the Eastern parking lots of Sears...
Underground Stormwater Treatment Vaults the size of two (2) underground City Halls are planned for Overlake Urban Center.
JULY 7, 2009 The Planning Commission is currently studying the second phase of the Overlake Urban Center Plan. 5,000 residents are expected to move into the Overlake center, many of them Microsoft workers. A proposed Group Health Tower (~10 stories) will anchor the Center. A light rail transit center is planned. The 36th Street Bridge is under construction.
On July 2, 2009 the Parks and Trails Commissioners listened to stormwater presentations for the Overlake Center, by senior stormwater engineer Steve Hitch and OTAK Consultants. All the new roads, buildings and other impervious surfaces will produce dirty stormwater. The runoff will contain oils, sediment, and chemicals that must be treated before it's discharged into streams. The underground "concrete box" (vault) appeared a recommended treatment of choice compared to open ponds. However, today Mr. Hitch commented that "vaults are very costly, and they hide the water, so open facilities are a good alternative."
Open ponds, rain gardens, plazas, walkways, trails, and other Overlake Village design features will be displayed during a public workshop and presentation. See you Thursday, August 6, 2009 5-8pm at the Silver Cloud Hotel, 2122 152nd Ave. NE, Redmond, WA. Overlake Room.
The underground vault(s) are large, equal in size to two (2) underground City Halls! That's correct, two City Halls. The vaults have many advantages. They will free up 3-4 acres of Open Space. A park-like atmosphere can be designed for the community to embrace. Trails, sidewalks, bike trails, plazas, and other connections can be installed right on top of the vault lid. However, the top priority for it's use remains a stormwater facility.
After the stormwater is treated in the massive vaults, it is discharged into Kelsey Creek, travels to the Mercer Slough and falls out into the East Channel of Lake Washington at 1-90. The City of Redmond is partnering with Bellevue on the route.
The closest I can come to an example of what a large underground vault looks like is this photo. This vault is located on Camwest's 32 -lot Perrigo Heights development. It's the size of "a pin" compared to the proposed Overlake Urban Center's vaults. Camwest's lid top is only about 30 x 60 feet. The Camwest HOA doesn't appear to be using the lid for resident activity, at this time. Treated stormwater from the vault by-passes Hartman wetlands and is discharged into Perrigo Creek, a tributary of Bear Creek.
My primary source for this entry are the audio-tapes from the Redmond Parks & Trails Commission meeting of July 2, 2009 CONTACTS: shitch@redmond.gov (on stormwater vaults) and tmarpert@redmond.gov (on Overlake Urban Center).
Overlake Village Urban Center & Kelsey Creek Watershed GOOGLE DOC LINK.
Your comments and feedback are welcome! It's hard to believe, isn't it?
Underground Stormwater Treatment Vaults the size of two (2) underground City Halls are planned for Overlake Urban Center.
JULY 7, 2009 The Planning Commission is currently studying the second phase of the Overlake Urban Center Plan. 5,000 residents are expected to move into the Overlake center, many of them Microsoft workers. A proposed Group Health Tower (~10 stories) will anchor the Center. A light rail transit center is planned. The 36th Street Bridge is under construction.
On July 2, 2009 the Parks and Trails Commissioners listened to stormwater presentations for the Overlake Center, by senior stormwater engineer Steve Hitch and OTAK Consultants. All the new roads, buildings and other impervious surfaces will produce dirty stormwater. The runoff will contain oils, sediment, and chemicals that must be treated before it's discharged into streams. The underground "concrete box" (vault) appeared a recommended treatment of choice compared to open ponds. However, today Mr. Hitch commented that "vaults are very costly, and they hide the water, so open facilities are a good alternative."
Open ponds, rain gardens, plazas, walkways, trails, and other Overlake Village design features will be displayed during a public workshop and presentation. See you Thursday, August 6, 2009 5-8pm at the Silver Cloud Hotel, 2122 152nd Ave. NE, Redmond, WA. Overlake Room.
The underground vault(s) are large, equal in size to two (2) underground City Halls! That's correct, two City Halls. The vaults have many advantages. They will free up 3-4 acres of Open Space. A park-like atmosphere can be designed for the community to embrace. Trails, sidewalks, bike trails, plazas, and other connections can be installed right on top of the vault lid. However, the top priority for it's use remains a stormwater facility.
After the stormwater is treated in the massive vaults, it is discharged into Kelsey Creek, travels to the Mercer Slough and falls out into the East Channel of Lake Washington at 1-90. The City of Redmond is partnering with Bellevue on the route.
The closest I can come to an example of what a large underground vault looks like is this photo. This vault is located on Camwest's 32 -lot Perrigo Heights development. It's the size of "a pin" compared to the proposed Overlake Urban Center's vaults. Camwest's lid top is only about 30 x 60 feet. The Camwest HOA doesn't appear to be using the lid for resident activity, at this time. Treated stormwater from the vault by-passes Hartman wetlands and is discharged into Perrigo Creek, a tributary of Bear Creek.My primary source for this entry are the audio-tapes from the Redmond Parks & Trails Commission meeting of July 2, 2009 CONTACTS: shitch@redmond.gov (on stormwater vaults) and tmarpert@redmond.gov (on Overlake Urban Center).
Overlake Village Urban Center & Kelsey Creek Watershed GOOGLE DOC LINK.
Your comments and feedback are welcome! It's hard to believe, isn't it?
Email from Steve Hitch, City Stormwater Engineer, today:
ReplyDeleteBob,
Thanks for your interest in this great project.
You will find much more information on our website at: http://www.redmond.gov/intheworks/overlake/stormpark.asp. We are developing more content for that page, and will add to it as our design progresses. The attached project information sheet will be posted to the website in the next day or so and is being mailed to Overlake businesses and residents. A draft was shared with the Parks & Trails Commission when Tim Cox and I presented with Otak at the meeting you listened to. We have a public meeting on August 6 at the Silver Cloud in Overlake (see the project information sheet).
As for your draft article, here are some thoughts:
We refer to the bridge as the 36th Street Bridge. There is information about it at: http://www.redmond.gov/insidecityhall/publicworks/construction/overlake.asp.
You indicate a large Group Health tower is planned. I don't know the status of their development at this time, except that I know they are working at concepts.
If you look over our Project Information Sheet, you will see some of the concepts we are looking at. These include open pond facilities and vaults, not just vaults. Vaults are very costly, and they hide the water, so open facilities are a good alternative. A good local example of an open facility is the Thornton Creek Water Quality Facility http://www.seattle.gov/util/About_SPU/Drainage_&_Sewer_System/Projects/COS_002477.asp or the High Point pond http://www.ci.seattle.wa.us/util/About_SPU/Drainage_&_Sewer_System/Natural_Drainage_Systems/High_Point_Project/index.asp. A good example of a large local vault facility collocated with a park is the Cal Anderson drinking water reservoir http://www.cityofseattle.net/parks/proparks/projects/andersonreservoircover.htm.
_________________________
Steve Hitch, P.E.
Sr. Stormwater Engineer
City of Redmond
Public Works Department
Natural Resources Division