Sometime in 1978, the National Power Corporation (NAPOCOR), a government-owned and controlled corporation, dug subterranean tunnels under the land of the Maruhom clan without the latter’s knowledge and consent. In 1992, these tunnels were discovered by the Maruhom clan. NAPOCOR was using the tunnels to funnel water from Lake Lanao into their power generation projects. The Maruhoms sued NAPOCOR for recovery of possession and damages.

NAPOCOR argued that, at 115 meters below the surface, the Maruhom clan’s right to the subsoil does not extend beyond what is necessary to obtain all the utility and convenience that such property can normally give. Is NAPOCOR correct?

No. The Civil Code states:

ART. 437. The owner of a parcel of land is the owner of its surface and of everything under it, and he can construct thereon any works or make any plantations and excavations which he may deem proper, without detriment to servitudes and subject to special laws and ordinances. He cannot complain of the reasonable requirements of aerial navigation.

Thus, the ownership of land extends to the surface as well as to the subsoil under it. In fact, the case stemmed from an attempt by the family to apply for a permit to dig deep wells on their property. This was denied by the water district, citing safety concerns because of the tunnels. This demonstrably shows that the ownership rights of the landowner was indeed impaired by the tunnels.

• NAPOCOR v. Ibrahim, G.R. NO. 168732, June 29, 2007.