P.R. Laws tit. 31, § 1311
To the public domain belong:
(1) Rivers and their natural beds.
(2) Continuous or intermittent waters from sources or brooks running in their natural beds, and the beds themselves.
(3) Waters rising continuously or intermittently in lands within the same public domain.
(4) Lakes and marshes formed by nature on public lands, and also their beds.
(5) Rain water running through ravines or sandy beaches, the beds of which may also belong to the public domain.
(6) Subterranean waters existing on public lands.
(7) Waters found within the zone of operation of public works, even when they are executed by a grantee.
(8) Waters flowing continuously or intermittently from tenements belonging to private parties, to the people of the United States, to the Commonwealth of Puerto Rico, or to the municipalities thereof, from the moment they leave such tenements.
(9) The waste waters of fountains, sewers and public institutions.
History —Civil Code, 1930, § 341;.