I helped a client with a similar issue. His ranch was the headwaters of a drainage which included hydropower, and he got improvement grants from the State for restoring the natural landscape. Since it was not associated with the ranching operations, not related to business, it isn't ordinary and necessary expense. It's land improvement, but in his case, not a depreciable asset. Your taxpayer's change might not be permanent, though. It might have only a useful life depending on what happens to the land down the timeline.

I found this article for you, which looks useful:

https://www.calt.iastate.edu/article/tax-rules-implementing-conservation-or-climate-smart-practices