PROPERTY, PLANT, AND EQUIPMENT
The following table sets forth the major classifications of property, plant, and equipment and accumulated depreciation of continuing operations at December 31:
In thousands20252024
NW Holdings:
Plant in service$5,468,170 $4,769,565 
Construction work in progress172,265 149,354 
Less: Accumulated depreciation1,288,422 1,246,592 
Total property, plant, and equipment, net$4,352,013 $3,672,327 
Capital expenditures in accrued liabilities$57,762 $26,610 
NW Natural:
Plant in service$4,879,816 $4,577,955 
Construction work in progress120,513 128,764 
Less: Accumulated depreciation1,256,289 1,222,413 
Total property, plant, and equipment, net$3,744,040 $3,484,306 
Capital expenditures in accrued liabilities$33,582 $24,625 

NW Natural
NWN Gas Utility balances primarily consist of transmission and distribution plant, gas storage facilities, general plant and other fixed assets. In October 2024, the OPUC issued an order concluding the NW Natural 2024 Oregon rate case. The OPUC ordered a regulatory disallowance related to $13.7 million of undepreciated line extension costs, which resulted in a reduction of NWN Gas Utility plant in service and a non-cash, pre-tax charge that was recorded as operations and maintenance expense in the consolidated statements of comprehensive income in the fourth quarter of 2024.

The weighted average depreciation rate for NWN Gas Utility assets was 3.1% in 2025, 2.9% in 2024, and 3.0% 2023. The weighted average depreciation rate for assets not related to NWN Gas Utility was 1.9% in 2025, 1.7% in 2024 and 1.7% in 2023.

Accumulated depreciation does not include the accumulated provision for asset removal costs of $561.6 million and $526.5 million at December 31, 2025 and 2024, respectively. These accrued asset removal costs are reflected on the balance sheet as regulatory liabilities. See Note 2.

NW Holdings
Plant balances include long-lived assets associated with SiEnergy and water and wastewater and operations.

Historical Timeline

Fiscal YearFiled
2025Feb 27, 2026Showing above
2024Feb 28, 2025
2023Feb 23, 2024
2022Feb 24, 2023
2021Feb 25, 2022
2020Feb 26, 2021
2019Mar 2, 2020
2018Mar 1, 2019

About PP&E Disclosures

The PP&E disclosure details a company's physical asset base — land, buildings, machinery, and equipment — along with the depreciation methods and useful life assumptions that determine how these costs flow through the income statement. Capitalization policy thresholds reveal management's judgment on the boundary between expense and asset, directly affecting both reported earnings and asset values.

Key signals: changes in estimated useful lives or depreciation methods can materially shift reported earnings without any operational change. Compare capital expenditures against depreciation expense — when capex consistently trails depreciation, the asset base may be aging and underinvested. Watch for large asset impairments or write-downs that signal overvalued carrying amounts. Asset retirement obligations reveal future environmental or decommissioning costs that are often underappreciated. Compare PP&E intensity (PP&E-to-revenue) against industry peers to assess capital efficiency and competitive positioning.