E. 40th Project

April 8, 2024: Backfilling and landscape design is underway.

With tank construction complete, we are moving forward with the next phases of work. 

The area around the tanks are being backfilled so that only about 12-15 feet of concrete remains visible. Backfilling started in early March and will take 3-6 months with increased dump truck traffic. 

The tanks will then be fenced and screened with vegetation and portions of the site will be re-landscaped for public use.

Landscape design

In March EWEB issued a questionnaire to our project email list to collect input on landscape restoration and enhancement of the site.

The questionnaire focused on specific elements such as plant selection, pathways, and overall aesthetics. This feedback is helping designers understand what features resonate with the community and what adjustments may be necessary.

EWEB will use this input to develop the final landscape design plan and share it with the community.

Draft Design Concept

The draft concept represents the area where two unique plant communities come together with a gradual transition from the meadow edge to a dense tree canopy. It includes diverse native plants, prioritizing drought-tolerant species.

The water tanks will be visibly screened with vegetation as required by City of Eugene development code.

Click any of the images below to view a larger PDF.

  

Read previous news and announcements

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Facts about the project

• The property, which EWEB purchased in the 1950s specifically for this use, is more than 10 acres and approximately 2.5 acres is used for water storage.

• The two 7.5 million gallon tanks are concrete and will be partially buried, surrounded by wrought-iron fence, and have vegetative screening to blend in as much as possible with the existing landscape.

• A new 36-inch water transmission main is being constructed between West Amazon St. and the intersection of East 40th Ave. and Patterson St.

• 265 trees were removed for construction of the tanks (approximately 25% of the total trees on the site).

• Downed wood was kept in the community. Most was donated to a City of Eugene wetlands restoration project, where they will continue to provide habitat long into the future, and for public use projects in the Southeast Neighborhood and also the City of Springfield.

• After construction, the remainder of the property (approximately 8 acres) will remain open to the public. Habitat will be restored or enhanced to support a diverse community of native plants and animals, with a focus on restoring oak and prairie-dominated habitat that historically characterized the area.

• The entire construction process will take around 3 years from earthwork to re-landscaping.

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Building for earthquake resiliency

There's always the possibility that a natural or human-caused disaster could affect us here in the Pacific Northwest. The most significant hazard that could affect EWEB facilities is a Cascadia Subduction Zone earthquake. Here are some of the design and engineering features that make Eugene's newest base-level drinking water storage tanks safe, reliable, and earthquake-proof:

1. Elevation of 607 feet allows gravity to transport water to the network of pipes without relying on electric pumps.

2. Two smaller tanks instead of one large one provides redundancy.

3. Heigh and roof designed to withstand seismic-induced slosh waves.

4. Tanks are constructed out of reinforced, pre-stressed concrete to achieve a high load capacity both laterally and vertically.

5. Each tank is wrapped in 90 miles of high-strength steel wire, which is then encased in shotcrete.

6. Flexible pipe couplings have double-ball joints that can move in every direction.

7. Secure fencing protects water from contamination, vandalism, and other threats.

8. Anchored flexible base connection between the floor and wall allows load transfer in a seismic event. 

9. Remotely operated seismic valves can isolate the tanks from the distribution system downstream.

Watch a video about earthquake-proof features of East 40th water storage tanks.

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Important considerations

As is common with major infrastructure projects, EWEB invested years in the research and planning process for the water storage at East 40th, including an ecological survey, geological report and a Triple Bottom Line assessment to evaluate construction options from the perspectives of habitat impacts, costs and disruption to the site and to neighbors. The research and planning process was invaluable to our ability to make a well-informed and sustainable decision for the entire community that we serve.

Here are some of the considerations that went into the design of the E. 40th water storage facility:

• • Drinking water safety and quality - This is paramount. All final decisions around aesthetics and public access ensure that drinking water and the facilities/equipment that distribute that water are secure and protected from contamination and service disruptions. 

• • Elevation - The top of the water surface must be at 607 feet above sea level and the tank height must match other planned and existing tanks to meet the hydraulic pressure requirements of gravity-supplied drinking water storage.

• • Access - Adequate access is required for maintenance and emergency vehicles.

• • Future planning - The site layout accommodates space for future replacement in 50+ years.

• • Proximity to residences - To the extent possible, tank siting maximizes the distance between construction and location of tanks and neighbors' property lines.

• • Viewsheds - Minimizes permanent visual impacts by preserving trees and minimizing the number of neighbors who have changes to their viewscapes.

• • Truck traffic - Minimizing construction truck trips generated by the removal of mass excavation spoils and the import of backfill material. 

• • Construction duration - Minimizing traffic, noise, dust, vibration and disruption on Patterson Street during utility installation. 

• • Habitat - Minimizing impacts to Strategy Habitats (according to Oregon Department of Fish and Wildlife's Oregon Conservation Strategy) that are of greatest conservation need and provide important benefits to Strategy Species.

• • Equipment emissions - Minimizing CO2 emissions from construction equipment and trucks.

• • Trees - Minimizing the removal of trees overall and remove trees only when it is necessary to do so.

• • Comparative construction costs - All EWEB customers bear the cost of these improvements. As always, we seek to be efficient and manage operating costs for the benefit of all customers and without creating inequity or disparities across geographic or income groups.

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Tank siting and construction

The tanks are sited on the eastern-most portion of the site, on the north side of the ridgeline and both tanks were constructed concurrently. 

Why this location?

A Triple Bottom Line (TBL) assessment developed by an outside engineering firm revealed there was approximately $1 million difference in construction costs between various tank location options, and no significant difference in the construction process or the total number of trees impacted. However, the location on the eastern-most portion of the site came out ahead in all TBL criteria evaluated, and has a few distinct advantages:

• Minimizes impacts to an Oregon Strategy Habitat
• Requires the least amount of rock excavation, reducing the duration, noise, and cost of construction
• Impacts the viewshed for the fewest neighbors

Why construct both tanks concurrently?

In addition to the TBL prepared by the outside engineering firm to help determine tank placement, EWEB prepared a second Triple Bottom Line assessment to understand the impacts of constructing both tanks concurrently, compared to the preliminary plan of constructing one tank in 2021, and a second tank in 2030.

For both options, we assessed costs, duration of construction, total number of truck trips, impacts to Patterson St. traffic, and disruption to the site and to neighbors. Looking at several criteria, we determined that building both tanks concurrently had some notable advantages:

• Provided 15 MG of secure water storage in the least amount of time (replacing College Hill)
• Saved approximately $1,400,000 (2021 Net Present Value)
• Consolidated the work into a single disruptive period, avoiding a second round of neighborhood disruption
• Limited Patterson St. wear and tear and coincides with City of Eugene street repairs
• Resulted in 2,100 fewer truckloads, reducing noise, street damage, and carbon emissions

Constructing both tanks concurrently disrupted the site for a total of 3 years, compared to a total estimated disruption period of 4 years under a staggered construction schedule.

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Community involvement

We are committed to ensuring all customers have access to information about the project, including timeline, benefits, and costs. Those who are highly interested and directly affected, such as site neighbors, will receive up-to-date project details, and have opportunities to share feedback, concerns, and aspirations. 

Prior to construciton, neighbors enjoyed open access to the vacant property. Understanding that public access has been a valued community benefit, EWEB is evaluating options for maintaining areas of open space at the project site. We intend to work together with neighbors and other stakeholders to re-landscape portions of the site for public use while ensuring responsible use of public funds.

For any property retained by EWEB and not used for storage facilities, site neighbors and other residents will be invited to participate in decisions that involve:

• Landscape design such as earth, rock, water, and vegetation features
• Public amenities (outside the fenced tanks) such as interpretive displays, walking paths

Opportunities to be involved and share feedback will be advertised on this website and other channels.

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