INTANGIBLE ASSETS

We acquired certain water rights, recorded at $16.9 million, and other intangible assets, recorded at $6.4 million, in the Intrepid South asset acquisition that we completed in May 2019. We account for our water rights as indefinite-lived intangible assets.

We account for the other intangible assets acquired in the Intrepid South asset acquisition as finite-lived intangible assets and amortize those intangible assets over the period of estimated benefit, using the straight-line method. The weighted-average amortization period for the other intangible assets acquired in the Intrepid South asset acquisition was 20 years. These intangible assets are included in "Other assets, net" on the consolidated balance sheets.

As of December 31, 2019, and December 31, 2018, we have the following amounts recorded for intangible assets (amounts in thousands):



	December 31, 2019					December 31, 2018
Finite-lived intangible assets:	Gross Carrying Amount		Accumulated Amortization			Gross Carrying Amount		Accumulated Amortization
Produced water disposal royalty agreements	$	2,700	$	(90	)	$	—	$	—
Surface damage and easement agreements	3,735		(124		)	—		—
Total	$	6,435	$	(214	)	$	—	$	—

Indefinite-lived intangible assets:
Water rights	$	19,184				$	2,311

Total amortization of intangible assets for the year ended December 31, 2019, was $0.2 million. We did not record any amortization of intangible assets for the year ended December 31, 2018. We estimate the annual amortization expense of intangible assets will be $0.3 million for each of the next five years.