Property, plant and equipment was comprised of the following as of September 30, 2025 and 2024:
 September 30
 20252024
 (In thousands)
Storage plant$790,621 $708,617 
Transmission plant6,308,557 5,713,831 
Distribution plant19,788,099 17,304,207 
General plant1,102,931 1,019,018 
Intangible plant38,612 38,612 
28,028,820 24,784,285 
Construction in progress1,235,316 1,063,798 
29,264,136 25,848,083 
Less: accumulated depreciation and amortization(3,971,146)(3,643,716)
Net property, plant and equipment (1)
$25,292,990 $22,204,367 
    
(1)     Net property, plant and equipment includes plant acquisition adjustments of $(21.1) million and $(22.9) million at September 30, 2025 and 2024.

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.