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We will update the Vault FAQs throughout the project as needed to help keep the community informed.



New FAQs as of October 15, 2019

What is the project status now?
As of October 14, 2019, we began the pouring of concrete for the project. This marked the beginning of the BUILD Phase. It is anticipated this phase will take approximately one year, weather permitting.

What happens during the BUILD PHASE?
During this phase, the contractor is building the entire concrete vault.

What are construction/ truck traffic impacts to expect during the BUILD PHASE?
Some construction impacts may include truck traffic, dust and noise. There will be about 70 percent less trucks coming in and out of the construction site than during the DIG phase. Concrete trucks will be on site two to three days a week and should leave the construction site by 2 p.m.

Will the BUILD phase create a lot of dust?
Dust levels will be significantly lower than the DIG phase which took place this summer. Control measures are in place per the environmental impact report. Construction will occur in accordance with the City’s standard specifications for public works projects. The specifications require the contractor to control dust at all times. There are enforceable penalties that can be levied on the contractor of up to $15,000 per day (city and state fines combined) if the contractor fails to properly implement appropriate erosion, sediment and/or pollution control measures. The contractor will be street sweeping to reduce the amount of dust/dirt tracking out from the construction site.

Do you expect noise from BUILD phase activities?
Yes. Noise is anticipated from the construction equipment used to BUILD the Vault. We will alert neighbors, businesses and park users of noise impacts through a variety of communications channels. See “How can the community get updates throughout construction?” below.

Why is there beeping coming from the construction site?
The beeping from the construction vehicles is an OSHA requirement when vehicles are backing up.



How long will construction last?
We anticipate construction to last an estimated 24 months.

What park areas will construction affect? What will the Vault look like when it is completed?
The Vault will be constructed beneath the George “Butter” Cole Field along 33rd Street between the picnic and rose garden areas. Construction is causing temporary disruptions on the east side of McKinley Park. We are committed to reducing impacts. During the final ENHANCE phase, park enhancements will be completed in McKinley Park.

Will the community be able to use McKinley Park during construction?
Yes. The community has had access to McKinley Park areas not under construction. At the intersection of 33rd Street and Park Way, jogging path users have been routed around the pan handle.

What above-ground structures are being constructed as part of the McKinley Water Vault Project?
A bathroom facility that will blend in with the look of the park. This structure will also house the electrical controls for the Vault.

How many trees will be planted as part of the McKinley Water Vault Project?
Approximately 63 trees and 207 shrubs will be planted. The types of trees and shrubs include the following:
Ginkgo Biloba Tree
Red Chinese Pistache Tree
Blue Oak Tree
Valley Oak Tree
Shumard Red Oak Tree
Sawleaf Zelkova Tree
Deodar Cedar Tree
Natchez Crape Myrtle Tree
Katrina African Iris (Shrub)
Putah Creek Myoporum (Shrub)

Will construction affect parking and neighborhood traffic?
Yes. Through the earlier phases, we worked closely with neighbors and community members to obtain their feedback about how to ensure the least amount of parking and traffic impacts. We will continue to alert neighbors, businesses and park users about impacts before and during all remaining phases. See “How can the community get updates throughout construction?” below.

How can the community get updates throughout construction?
Construction updates will be provided through a variety of channels. We are continually updating this website and are sharing updates through the media, signage, social media, electronic communications, Nextdoor, public workshops and direct mail.

The best way to get the latest information, is to sign up for email notification updates at, visit the project website at or call 916-808-5545. You can also follow the Department of Utilities on Facebook and Twitter.


Review the park enhancement renderings. 


Who decided on the park enhancements?

Utilities worked closely with the community and the Department of Youth, Parks and Community Enrichment. As part of the initial outreach process in fall 2016, stakeholder interviews with key organizations and community leaders were held. The interviewees included neighborhood organizations, business associations, fitness groups and real estate representatives. 

During the September 20, 2017 McKinley Water Vault public meeting, we solicited input about park enhancement ideas. Attendees stated they are interested in more trees, new bathrooms, an improved running track, more BBQs, better irrigation and a multipurpose field. People stated a multipurpose field could be used for youth soccer, community events, concerts in the park, park celebrations, festivals or other events that require an open turf area. Interviewees also stated the need for new restrooms, irrigation fixes and improvements to the jogging/walking path.


Based on the community feedback provided, the Department of Youth, Parks and Community Enrichment ultimately came up with the following park enhancements:


  • New multipurpose field for baseball, soccer and other sports and activities

  • Improving jogging path

  • Building restroom facility

  • Replacing corporate picnic area with new tables, benches and BBQ pits

  • Adding new shade structures

  • Planting approximately 60 new trees

  • New landscaping


Why was the George “Butter” Cole sign removed and where is the backstop from the baseball field?
The George “Butter” Cole sign is being preserved and stored during construction and will be put back once the project is complete. The wood from the baseball field backstop has been removed and stored.


Why isn’t the baseball field going to be re-installed? 
The Youth, Parks and Community Enrichment Department has determined a multipurpose field will be more effective for park users. A multipurpose field can accommodate community events, baseball, soccer games, gatherings and festivals.


Why are the new bathrooms proposed where they are?
They will provide close access to the multi-purpose field, group picnic areas, tennis courts and jogging trail. There is already a restroom next to the basketball court to serve the playground and other uses on the west side of the park.


How many stalls will the new restroom have?
There are four unisex stalls.


Why are the bathrooms facing the street?
It is good practice to place restroom buildings visible from the street. It allows for natural surveillance by pedestrians and residents. It also allows the Sacramento Police Department and park patrol to have clear sight lines when driving along the street.


How many shade structures will be installed?
There will be two shade structures similar in size to the playground picnic area shade structure




What is the McKinley Water Vault?
The Vault is basically a large underground cistern. It’s a temporary storage facility that will reduce wastewater outflows and storm water flooding during a large storm event, then it will slowly feed the wastewater into the combined sewer system at a rate that is sustainable as the storm subsides. The Vault will be designed for a 6-hour, 10-year storm event.


What are the benefits of the McKinley Water Vault?
The Vault will increase public safety by significantly reducing combined sewer outflows onto low-lying streets and adjacent properties that occurs during major storm events. It will also reduce street and park flooding which benefits neighbors, walkers, park goers and business patrons visiting the area.


How big will the Vault be?
The offline storage facility will have a 240’ x 300’ footprint and have ~2’ of soil cover above it. It will be able to hold approximately 6 million gallons when needed during large storms.


Review a video on how the Vault will work.


Where in the park will it be located?
The offline storage facility will be located beneath the George “Butter” Cole baseball field on the east side of McKinley Park, north of the Rose Garden and south of the picnic table area.


Why is McKinley Park the preferred project location? Why not McKinley Village?
Utilities identified the need for underground storage to reduce street flooding and outflows in the McKinley Park and East Sacramento neighborhoods. The initial concept included a deep tunnel under Alhambra Blvd. with a large diameter pipe and additional underground storage in the McKinley Village development. This concept was further evaluated in the 2015 Combined Sewer System Improvement Plan (CSSIP) Update. Because of the high cost for the deep tunnels, Utilities studied four other possible locations in East Sacramento as part of the 2015 CSSIP, and McKinley Park was identified as the best location.


Why is the Vault necessary in East Sacramento?
East Sacramento is at the top end of the combined sewer system that flows to the Sacramento Regional Wastewater Treatment Plant. When the combined sewer system is at maximum capacity, flooding and outflows occur in East Sacramento from local runoff and sewage. The McKinley Water Vault will reduce flooding and outflows by temporarily storing the wastewater.


What will the McKinley Water Vault store?
The Vault will reduce the amount of wastewater (storm water runoff and sewage) that floods the streets in the combined sewer system by temporarily storing it during large storm events. The Vault will be kept empty except during large storm events and will be drained when there is capacity in the combined sewer system.


Do you anticipate odor coming from the Vault?
No, but it will have an odor control facility included as part of the project. There have been no odor issues reported at the three existing vaults in the City of Sacramento.


What does the odor control facility do?
A fan will draw air from the offline storage facility and push it through granular activated carbon beds that absorb odor-causing compounds. The odor control facility will be located below ground near the new above-ground bathrooms.

Review an illustration of how the odor control facility works.
Review a video on how the combined sewer system will work.


Why is the project paid for by rate payer dollars, not by developers or industry?
Flooding in East Sacramento is an existing problem that was identified long ago. Developers are required to mitigate their impacts to the system with new development. For example, the McKinley Village development was required to build separated sewer and storm drainage systems. The storm drainage is pumped to the American River. As part of the 2015 water and wastewater rate increases, City of Sacramento Department of Utilities customers approved rate increases to fund projects like the McKinley Water Vault project to improve the Combined Sewer System.


How does groundwater affect the project cost?
Higher groundwater tables require a more extensive design and construction process which drives up costs. The groundwater table rises as it nears the river. We are trying to avoid digging in water saturated soils as much as possible to reduce the project cost. 


Are the funds for the park enhancements part of the existing McKinley Water Vault project budget? 
Yes.  One million dollars is allocated for park enhancements.


What is an outflow?
Wastewater flowing out of the combined sewer pipes and onto surface streets. Outflows occur when the combined sewer flows exceed its capacity.


What is a 6-hour, 10-year storm event?
It is one of the standard “design storms” Utilities considers in assessing the effectiveness of modifications to the combined sewer system. This represents the amount of rainfall from a storm event that lasts six hours and returns once every 10 years. It is based on the statistics of nearly 100 years of Sacramento rainfall data from the National Weather Service. It is terminology used to categorize a “design storm” for engineering analyses.


What is the combined sewer system?
The combined sewer system collects and carries wastewater (sewage) and storm water runoff through a single pipe network for treatment at the Sacramento Regional Wastewater Treatment Plant and the City’s wet weather treatment facilities during significant storm events. 

The system serves over 200,000 City residents including people in the downtown, East Sacramento, Land Park, Curtis Park and Oak Park neighborhoods. Combined sewer systems are rare on the west coast. San Francisco and Sacramento are the only large cities in California that have one. Many parts of the system are aging and do not have the capacity to protect the community from street flooding.