Topography
The basin area has a gentle a slope to steep slopes with an elevation range of to more than above sea level. Soil types includes Guimbalaon clay, Taburos clay and Bay clay loam. The basin's large area are unclassified with its mountainous land with a closed canopy of trees that covers almost the entire basin.Flooding
The towns of Iwahig ang Montible were found susceptible to flooding by the study conducted by the Mines and Geosciences Bureau.References
{{reflist, refs= {{cite journal , last1=Dangan-Galon , first1=Floredel , last2=Dolorosa , first2=Roger , title=Species richness of bivalves and gastropods in Iwahig River-Estuary, Palawan, the Philippines , url=https://www.academia.edu/28729619 , access-date=4 December 2021 {{cite web , title=LiDAR-Surveys-and-Flood-Mapping-of-Iwahig-Penal-Rive , url=https://dream.upd.edu.ph/assets/Publications/LiDAR-Technical-Reports/UPLB/LiDAR-Surveys-and-Flood-Mapping-of-Iwahig-Penal-River.pdf , publisher=University of the Philippines Training Center for Applied Geodesy and Photogrammetry , access-date=4 December 2021 {{cite journal , title=The Master Plan Study of Power Development In Palawan Province Republic of the Philippines , url=https://openjicareport.jica.go.jp/pdf/11767050_01.pdf , access-date=4 December 2021 Rivers of the Philippines Landforms of Palawan