Storm damage recovery

Basin 3 / Tryon Headwaters Stormwater Improvements

Sewer and Stormwater
In partnership with property owners and residents, we are working on a range of investments that will help improve stormwater management in the Basin 3 and Tryon Headwaters area to slow stormwater, reduce flooding, and improve water quality as it discharges to local Spring and Tryon creeks.
Construction is scheduled to start March 22nd, 2021 and will take about one month to complete.

Project Area

What’s Happening Now 

You may see crews in the area conducting pre-construction activities. Activities may include inspecting pipes and manholes, marking underground utilities with paint on the street or flags in the ground, setting up traffic controls, setting up erosion controls, staging equipment and materials, and other activities as needed. For more details, visit Pre-Construction Activities.

Look-Ahead Schedule 

Over the next few weeks, crews are scheduled to work at the following locations:  

  • Construction to improve the existing ditch, add a new storm pipe across SW 35th, and replace a portion of the stormwater pipe on SW 35th.  

  • Two new stormwater pipes will be installed on SW Spring Garden Ct to intercept some of the stormwater that currently flows through private properties and redirect it into the right-of-way.  

The look-ahead schedule is approximate, and the dates of particular activities may change due to weather, conditions underground, subcontractor schedules, materials and labor availability, and other factors. 

We Want to Hear from You 

Please contact us if you have any questions or concerns related to business operations, disability or mobility issues, and medical or business deliveries. Your input will help us design a successful stormwater project that minimizes the impact to your neighborhood during construction.  

Be sure to include your name, property address, and project name (Basin 3) in your voicemail and email so we can provide you more details about what to expect in front of your property. Also, please write “Basin 3” in the subject line of your email.

Construction Methods 

Open trench excavation will be used to replace the stormwater pipes. This method consists of digging down to and exposing the existing pipe, removing the existing pipe or a section of it, installing a new pipe or a section of new pipe, and then backfilling the trench. To read more about this construction method, visit Open Trench Excavation.

What to Expect 

You may expect the following activities and impacts during construction:  

  • Work Hours: From 7 a.m. to 6 p.m. Monday through Friday, and the same hours on Saturday if necessary.   

  • Traffic Delays and Detours: Expect traffic delays and a street closure in and near the work area.   

  • Driveway Access: Local access to your property will be maintained, but construction may impact normal use of your driveway or entrance to your home or business.  

  • No Parking: Little or no on-street parking will be allowed in and near work zones, especially during work hours.   

  • Equipment Storage: Equipment and materials may be stored on streets overnight.   

  • Services Maintained: Sewer, water, and other utilities are expected to remain in service during construction.     

  • Assistance: A city inspector will be on-site during work hours and may be able to assist you with an immediate need during construction.   

  • Emergency: In case of a sewer backup or basement flooding emergency, contact City Maintenance at 503-823-1700, press 1, and give them the project number E11090. The hotline is staffed all hours and all days. 

Project Background 

In January 2018, Environmental Services initiated a stormwater study in Basin 3 and the larger Tryon Headwaters area (Tryon Creek above I-5). This work is complementary but separate from the SW Capitol Highway project. The  SW Capitol Highway: Multnomah Village to West Portland  project is a joint effort by Environmental Services, Portland Water Bureau, and Portland Bureau of Transportation (PBOT) for street and stormwater improvements along SW Capitol Highway between SW Garden Home and SW Taylors Ferry Road. 

During the planning of the SW Capitol Highway project, Basin 3 (one of the four subbasins that SW Capitol Highway drains to) was identified as having a variety of known, persistent drainage issues. 

Throughout 2018, Environmental Services staff collected data and information, ranging from historical reports from residents of stormwater issues in the neighborhood to new data from flow monitors. We gained a better understanding of the existing public-private patchwork system, how water moves through it, and how much water needs to be managed. 

Bureau staff worked with the local community to find ways to manage stormwater throughout the neighborhood, instead of just one property at a time. Staff identified a range of public and private investments that will help improve stormwater management. These investments have been grouped together into short-, medium-, and long-term projects. This will help us address immediate needs while we monitor and determine if additional long-term solutions are necessary. 

BES started implementing several of the short- and medium-term projects in 2019/2020 and the construction work in the spring of 2021 is a continuation of this effort. 

Other Work in the Area