Molalla Transmission Main - wifia 3-1 (CI 22-014) 

This project is part of the City’s effort to improve drinking water service to its utility customers.  Currently, the city struggles to deliver water to its customers and storage reservoirs located south of Mountainview Street during peak usage periods in the summer. This project will replace an aging undersized 16” inch transmission main with approximately 4,500 linear feet of new 30” pipe, allowing the city to deliver more water to the area.  In addition, the city will replace approximately 2,400 linear feet of old 6-inch cast iron water main with a new 8-inch main, including replacement of 31 water services.  

The project requires construction in Holmes Lane between the city’s Mountainview Reservoir and Molalla Avenue and Molalla Avenue between Holmes Lane and Beavercreek Road.   During construction, one lane of traffic will be maintained in Molalla Avenue in each direction.  Night work is planned at signalized intersections along Molalla Ave to minimize impacts to traffic.  See the Project Map (below) for project alignment and night work locations.  

This Project is funded in part through a federal loan from the Water Infrastructure Innovation and Finance Act (WIFIA). Learn more about our WIFIA funding: Water Infrastructure Finance and Innovation

This project is a critical investment in the city's water infrastructure—one that will strengthen the city's ability to meet current and future water needs.

This project will improve the city's water system by replacing the current undersized water main, that’s over 60 years old. These upgrades will: 

• Ensure the water system is better equipped to handle peak water use, especially during high-demand summer months and emergencies.
• Improve the delivery of water, to both the city's water storage reservoirs and utility customers, year-round thus increasing reliability of water delivery and reducing the risk of service interruptions.
• Extend new water service to 31 customers to support the city’s continued growth and development.

This upgrade is not just about fixing old pipes—modernizing aging infrastructure is a long-term investment in the health, resilience, and sustainability of our community.  

DOCUMENTS 

• Business Letter with Survey - December 11, 2023

MAPS

• Project Map with Nightwork, September 2024
• Project Area Map

IMAGES 

• Pipeline Markings on Holmes Lane - Preconstruction
• Utility Potholing in Molalla Avenue

WEBLINKS 

• Construction Projects Traffic Impacts Map
• All City Projects Interactive Map

Groundwater is a naturally occurring source of water located below the ground’s surface. It can be impacted by stormwater (rain, snow) that soaks into the ground filling the tiny spaces between rocks, sand and dirt under the surface. Groundwater levels fluctuate throughout the year as the seasons become more wet (high groundwater level) or dry in the summer (low groundwater levels). It’s like water hiding in a sponge, but underground! 

Infiltration happens when groundwater leaks into the underground public sewer system through cracked pipes, broken manholes or improperly connected roof drains. Infiltration increases during winter and spring when groundwater levels are high. This increase can overload the sewer system, leading to backups and system failures. Because this additional water must be treated at the wastewater treatment plant, it increases costs for both the city and utility customers.

Inflow is when surface stormwater enters the sanitary sewer system through direct connections such as downspouts from roofs, sump pumps, or improperly connected stormwater pipes. Inflow can significantly increase flows during rainstorm events - potentially overloading the sewer systems and leading to sewage backups. Like infiltration, inflow raises treatment and maintenance costs, while placing additional strain on wastewater facilities. More critically, it threatens both environmental and public health. Inflow is the primary cause of peak surges in sewer flow during storm events. 

Lateral Lines (laterals) Sewer laterals are small pipes that connect a home or business to the public sewer system. These pipes carry wastewater or stormwater away from the buildings into the public mainline sewer systems. Typically, each home or business has a single sewer lateral.  In Oregon City, maintenance of sewer laterals is divided between the property owner and the City. 

Main lines are large pipes within our water, sanitary sewer and stormwater sewer systems designed for higher volumes.

Manholes are below ground structures used to access the City’s sewer systems for inspections and maintenance. You can identify manholes by the large round metal lids typically found within the roadway. Manholes are also used to change the direction of sewer pipes (like turning a corner); shift pipes from one side of the road to the other, or to combine flows (from two or more pipes into one main pipe (done for sanitary and storm sewer systems). 

Public Right of Ways (ROW) are portions of land dedicated for use like sidewalks, roads, and access to public utilities (such as water, sewer, etc.). Government agencies (city, county, state) are responsible for maintaining and managing these spaces. Think of it like the Oregon City Public Library. The city (government) owns it, but everyone can use it, and the city workers are like janitors who keep it clean, safe and working properly. The ROW is a shared community space and is protected by important rules and regulations. 

Rehabilitation (Rehab) restores the current system by improving the conditions to help make them last longer. 

Repairs, unlike rehabilitation, are long-term solutions.  These can include full pipe replacements, new pavement, etc. 

Sanitary sewer lines are underground pipes that carry wastewater away from buildings (homes, businesses, etc.), to be treated at a treatment plant. 

Sewage is a type of wastewater that typically contains human waste. Oftentimes the term sewage and wastewater are used interchangeably but not all wastewater contains sewage.

Sewer Systems consist of all the parts that make up the city's sanitary and stormwater collection systems. These include pipes, manholes, and pumps that are maintained by the city to transport different types of water (stormwater and sewage). Note: Sanitary Sewer Systems and Stormwater Sewer Systems are two different collection systems. 

Stormwater is rainwater that flows into gutters and the stormwater sewer system. As the water runs off rooftops, streets and other hard surfaces, it can collect dirt, oils, and debris, becoming polluted. To help clean this runoff, the city uses specifically designed raingardens, ponds, planters and other structures to treat the water before it releases back into the environment.

Stormwater collectors collect rainwater or channel rainwater. Examples include catch basins and roof gutters. 

Streetscape is broad term for the various components that make public spaces more welcoming.  While streets provide access from one place to another (focused on movement), streetscapes provide the experience and overall look of an area that can define a community’s identity, economic activity, social cohesion, public health, and quality of life (to include mobility). This is achieved by adding things such as street trees, planters, street furniture (i.e. trash receptacles, benches), sidewalks, and streetlights. Special elements can include public art, water fountains and drinking fountains.

Treatment is the process to remove pollutants from wastewater to make the water safe for reuse or release into the State’s waterways.

Wastewater is a combination of sewage and dirty/used water from toilets, sinks, washers, showers and other household or commercial sources. This water travels through the sanitary sewer system - which includes lateral lines and main lines - to a treatment facility.  

Wastewater Treatment Facilities (also referred to as "wastewater treatment plant" or "sewage treatment plant") are the locations where wastewater is treated (cleaned) to remove harmful substances (like human waste, chemicals, and food scraps). Once cleaned, it is safe enough to be sent back to the natural water cycle (usually into rivers or oceans) or be reused for things like irrigation.

PUBLIC OUTREACH ITEMS: 

The following Open House meetings were held: 

• June 4, 2024 – in person
• June 6, 2024 – Virtual  

May 2024 - Open house Postcard Mailer

Neighborhood Meetings were held:

• March 14, 2024 - Elyville Neighborhood Meeting Handout
• April 2, 2024 - Hillendale Neighborhood Hillendale Neighborhood Meeting Handout
• July 10, 2024 - McLoughlin Neighborhood Meeting Handout