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Powell Butte Reservoir 1 Roof Repair

Under Construction
An important part of our water system needs some work. The two reservoirs at Powell Butte fuel our region with safe and abundant water. Starting in summer 2021, the Water Bureau will repair the roof of Reservoir 1. We'll also install a better drainage system on the reservoir's roof.
Spring to fall 2021 and 2022
Location Description
Powell Butte Nature Park
Businesses Affected
Residences Affected
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Project overview

A map of the proposed truck route for the Powell Butte Roof Replacement project. The truck will go down Anderegg Trail, over to North Access Lane, then pipeline lane, wrapping back down East Access lane back down to Anderegg Trail.

Starting in summer 2021, we will repair the roof of Reservoir 1 at Powell Butte. Built in the early 1980s, this 50-million-gallon underground reservoir is the older of the two reservoirs on the site. We took it out of service when a regular inspection showed signs of leaks. Construction standards were different when the reservoir was built in the 1980s, and the waterproofing on the roof of Reservoir 1 needs to be brought up to current industry standards. An outdated drainage system on the surface allows water to pool above the reservoir during the rainy season.

We will excavate soil so we can repair and seal the roof with a waterproof membrane, upgrade access hatches and piping, and install a more effective roof drainage system. 

We’re investing in this project because in an emergency, having two reservoirs is better than having one. A second reservoir serves as a safety net for all the unexpected events that can happen on any given day. If the flow of water from the Bull Run or groundwater system is interrupted, we can use the water stored in the reservoirs until we resolve the problem. Having two reservoirs online means we have more water available, which means we have more time to adapt to emergencies while avoiding service interruptions. 

Happening now

  • We have selected a contractor and are studying truck routes and trail impacts.

  • The contractor may be on site to walk and mark the construction zone.

  • We are observing ground-nesting birds in the area.

  • We are developing outreach materials such as signage and videos about the project. We are reaching out to neighborhood associations and other community groups to offer presentations. 

  • Learn more about the project and ask questions at an upcoming community meeting:

    • Centennial Community Association meeting, 5:30–7:00 p.m., Tuesday, May 18
      Contact Centennial's Board Chair Daniel Bramske to RSVP and get a link for the meeting.
    • Pleasant Valley Neighborhood Association meeting, 7:00 – 8:30 p.m., Wednesday, May 19, Zoom Meeting ID: 898 4754 1032

DEQ 1200 C Stormwater Permit

The reservoir is covered with a thin layer of soil. We will need to remove that soil to access the reservoir roof for repairs. Because its volume is more than one acre (upward of 500,000 cubic feet), we have applied for an Oregon Department of Environmental Quality (DEQ) 1200 C Stormwater Permit. This permit guides how we manage stormwater and sediment erosion on our work site during construction. 

The public comment period for this permit began on April 29 and ended on May 13, 2021. Information about the permit and the comment process can be found on this DEQ webpage.

Coming up

Fencing installation 

Our contractor will install safety fencing around the construction area in June or July. 

Construction in July 

Construction begins in July. Workers will set up a safety fence around the construction area and begin removing dirt from the roof so we can access and repair the reservoir roof.

Project sequence

Work on this project will happen in two phases during the spring to fall of 2021 and 2022. Because we are working to protect nesting birds while also doing construction work that can only take place during dry weather we have a very short window of time in which to work during the summer of 2021. We will do as much work as we can this summer, pause our work in the rainy season, and begin again next spring.

This table lists the items described in the text below.

Work happening in 2021 

A Savannah Sparrow perches on a small shrub.
Savannah Sparrow
  • Spring: We have delayed our construction start date to July to protect the Savannah Sparrows who nest in clumps of grass on top of the reservoir in the spring. Our staff will survey the area two to three times, flag, and set up buffer zones around bird nesting areas within the construction area. That way, we can make sure the birds have left their nests before we start construction.

  • Summer to fall 2021: Construction

    • Preparation: Set up erosion controls, protective fencing, construction signage. 

    • Soil removal: Remove soil from the roof, stockpiling half of it on the northwestern corner of the construction area so it can be replaced when work is complete. The other half of the soil will be given to Portland Parks and Recreation to use for their 20-acre expansion of Parklane Park. 

    • Roof repairs: Inspect and repair the roof. 

    • Install winter erosion control, including the new drainage system: Prepare the construction site for a pause in work over the winter. Install the drainage system along the northern side of the reservoir to carry water into the existing stormwater system on site.

Work happening in 2022

  • Spring bird survey: Because the roof of the reservoir will not have soil or plants growing on top of it during the winter of 2021 to 2022, it is unlikely that birds will nest. However, we will survey for birds within the surrounding construction area before starting work in spring 2022. Prior to the nesting season, we will do what we can to encourage birds to nest elsewhere so that we can wrap up construction with the least amount of impact as possible during the coming summer.

  • Access hatch and piping upgrades: Upgrade the access hatches where staff enter the reservoirs for inspections and maintenance. This will involve pouring concrete and installing new hatch covers. Remove and replace electrical and washdown piping on the reservoir. 

  • Roof repairs: Complete roof repairs.

  • Waterproofing: Apply a waterproof rubber membrane on the outside of the reservoir roof. 

  • Roof drainage piping improvements: Install the drainage system on top of the roof and connect it to the existing stormwater system. When we built Powell Butte Reservoir 2 (located to the west of Reservoir 1), we installed stormwater infrastructure for this purpose. 

  • Preparing the reservoir to serve water: Power wash and sanitize the inside of the reservoir, then fill it with water. After the reservoir is full, test it to make sure it's ready to serve water.  

  • Native plant restoration: Top the drainage system of the reservoir with stockpiled soil and seed the roof and other disturbed areas. Our native plant mix is made up of grasses and wildflowers that benefit birds and pollinating insects. 

Español (Spanish)

Mejoras del sistema de agua: Reserva de Powell Butte 1 reparación de tejado

Una parte importante de nuestro sistema de agua necesita mantenimiento.  Las dos reservas de Powell Butte brindan a nuestra región agua abundante y segura.  En el verano de 2021, el Departamento de Aguas reparará el techo de la Reserva 1 de Powell Butte.  Repararemos y sellaremos el techo con una membrana impermeable, mejoraremos las trampillas de acceso y las tuberías e instalaremos un sistema de drenaje de techo más eficaz.  Estamos invirtiendo en este proyecto porque en caso de emergencia es mejor tener dos reservas que una. Una segunda reserva sirve como sistema de seguridad para cualquier evento inesperado que pudiera ocurrir un día en particular.

Tiếng Việt (Vietnamese)

Cải Thiện Hệ Thống Nước: Sửa Nóc Hồ Chứa Nước Powell Butte 1

Một phần quan trọng của hệ thống nước của chúng ta cần sửa chữa. Hai hồ chứa nước tại Powell Butte cung cấp nước sạch và đủ cho khu vực của chúng ta.  Bắt đầu từ mùa hè 2021, Thủy Cục sẽ sửa mái của Hồ Chứa Nước 1 tại Powell Butte.  Chúng tôi sẽ  sửa chữa và bịt kín mái với các chất liệu chống nước, nâng cấp cửa hầm vào và đường ống, và lắp đặt mộ hệ thống thông nước từ mái hiệu quả hơn. Chúng tôi đầu tư vào dự án này vì trong trường hợp khẩn cấp, có hai hồ chứa nước sẽ tốt hơn một. Một hồ chứa nước thứ hai sẽ là cứu cánh cho các trường hợp không thể lường trước có thể xảy ra bất cứ khi nào.  

简体中文 (Simplified Chinese)

水务系统提升 : Powell Butte Reservoir 1 号水库上盖维修

我们供水系统中的一个重要部分需作一些维护工程。   位于 Powell Butte(鲍威尔比尤特)的两个水库为我们的地区提供了安全充足的饮用水。由 2021 年夏季开始,水务局将会为 Powell Butte(鲍威尔比尤特)的 1 号水库进行上盖维护工程。我们将为水库进行维修,并会以防水膜密封其上盖,为检修出入口及管道进行升级工作,以及安装更有效的上盖排水系统。我们投资于此项目的原因,是由于在紧急情况下,拥有两个蓄水库总比只有一个为佳。 不论任何时候,每当有任何不可预知的事情发生时,第二个 蓄水库可担当安全网的角色。 

Русский (Russian)

Усовершенствование системы водоснабжения : Ремонт крыши резервуара 1 в Powell Butte

Важная составляющая нашей системы водоснабжения нуждается в обслуживании. Два водохранилища в Powell Butte обеспечивают наш регион обильной и безопасной водой.  Летом 2021 года Управление водоснабжением начнет ремонт крыши водохранилища 1 в Powell Butte.  Мы отремонтируем и уплотним крышу водонепроницаемой оболочкой, заменим люки и трубы, а также установим более эффективные водоотводы на крыше. Мы вкладываем средства в этот проект потому, что в экстренных ситуациях лучше иметь два водохранилища, чем одно. Второе водохранилище служит в качестве страховки на случай непредвиденных обстоятельств, которые могут возникнуть в любое время.