How PotlatchDeltic Utilizes Bridges and Culverts

Each year, more than seven million tons of logs travel safely across PotlatchDeltic’s extensive network of forest roads, crossing numerous streams using approximately 39,000 culverts and 100 bridges. Responsibly managed stream crossings are essential to sustainable forestry operations. PotlatchDeltic carefully designs, constructs, and maintains stream crossings to protect water quality, while balancing optimal environmental performance and operational efficiency.

Regional conditions significantly influence PotlatchDeltic's stream crossing strategies. In Idaho, steep terrain and seasonal weather restrict road-building windows to approximately four months during the year. Culverts, sized based on drainage area, fish presence, and regulatory standards, are commonly used for crossings because they are cost effective and easy to install. Bridges, reserved for larger streams or challenging terrain, also provide essential fish passage and durability. Annual inspections and rigorous design standards ensure culverts and bridges perform reliably under Idaho’s Forest Practices Act.

In the U.S. South, flatter terrain and extensive water networks present different challenges. PotlatchDeltic increasingly utilizes portable bridges, representing an evolution from traditional methods for temporary crossings that required extensive creek bank disturbance and sedimentation management. Portable bridges, owned and deployed by the company, offer quicker installation and removal, significantly reduce sedimentation risks, and improve operational access. Contractors prefer these portable solutions for their operational efficiency, reduced cleanup requirements, and minimal environmental footprint.

Maintenance and inspection are ongoing commitments integral to PotlatchDeltic’s stream crossing management. Bridges are inspected annually by external engineers, while culverts undergo routine evaluations within landscape assessments conducted on three- to five-year rotations, depending on environmental risk factors such as landslide susceptibility. Additionally, culverts and crossings are proactively inspected before and after timber harvest operations to promptly identify and address potential environmental concerns.

Through strategically designed, constructed, and thoroughly maintained stream crossings, PotlatchDeltic effectively balances sustainable forest management practices with economic objectives, safeguarding water quality and aquatic ecosystems for future generations.

FORWARD-LOOKING STATEMENTS

This release contains certain forward-looking statements within the meaning of the federal securities laws. Words such as “annually,” “ongoing,” “routine,” and similar expressions are intended to identify such forward-looking statements. These statements reflect management’s views of future events based on assumptions and are therefore subject to known and unknown risks, uncertainties, and other factors, and are not guarantees of future conduct, results, or policies. Please view the Cautionary Statement Regarding Forward-Looking Information on page 32 of PotlatchDeltic’s 2024 Corporate Responsibility Report.