Carollo Engineers selected to develop storm drainage system master plan for Cottage Grove, Oregon

The city of Cottage Grove, Oregon, announced on May 6, 2025, it has selected Carollo Engineers to develop a comprehensive storm drainage system master plan that will guide the city’s infrastructure planning and stormwater management strategy over the next 20 years.

The city has recently surpassed the 10,000-resident threshold, which triggers new regulatory requirements under Oregon’s Municipal Separate Storm Sewer System (MS4) program. Additionally, the city has adopted low-impact development guidelines and a Total Maximum Daily Load (TMDL) implementation plan.

The project will include a thorough assessment of the current stormwater system, identification of capital improvement needs, and development of a long-range plan that aligns with Oregon’s Public Facility Planning standards (OAR 660-011) as well as requirements from the Department of Environmental Quality, Department of Land Conservation and Development, and other regulatory bodies.

The city’s stormwater system spans more than 30 miles of drainage lines and includes approximately 600 catch basins, along with several open channels and ditches. With low-impact development policies already in place, the city is poised to further enhance its stormwater infrastructure, supporting sustainability, growth, and resilience.

Carollo’s approach to the plan emphasizes proactive planning, data-driven analysis, and sustainable infrastructure strategies. 

The city and Carollo will work closely with local stakeholders to integrate community feedback into the plan to reflect the values and priorities of Cottage Grove residents. The plan will also focus on strategies to improve water quality, protect local ecosystems, and mitigate the impacts of flooding, contributing to the long-term environmental health of the city.

“Our goal is to create a flexible, future-ready plan that enables Cottage Grove to manage stormwater effectively while supporting community growth,” said Carollo Project Manager Kurt Robinson in a press release. “We’re proud to partner with the city to develop a plan rooted in long-term environmental stewardship.”

City officials view this effort as a critical investment in the community’s future well-being.

“As our city continues to grow, developing a stormwater system that protects people, property, and the environment is essential,” said Public Works & Development Director Faye Stewart in a press release. “We look forward to working with Carollo to create a plan that not only meets state and federal requirements but also reflects our community’s values around sustainability, environmental stewardship, and smart infrastructure planning.”

In addition to assessing existing infrastructure and projecting future needs, the company will perform a rate study and assist the city in identifying funding sources while prioritizing capital improvement projects that deliver meaningful benefits to the community.

The storm drainage system master plan is expected to be completed by fall 2026.