▁lo am ▁and ▁g olds . ▁ ▁There ▁are ▁two ▁major ▁rivers ▁in ▁N agu ilian . ▁The ▁N agu ilian ▁River ▁is ▁located ▁in ▁the ▁western ▁portion ▁of ▁the ▁town . ▁It ▁flows ▁west ward ▁beginning ▁from ▁the ▁province ▁of ▁Beng uet ▁towards ▁La ▁Union ▁and ▁em pt ies ▁into ▁the ▁South ▁China ▁Sea , ▁dra ining ▁the ▁valle ys ▁of ▁Bar ang ays ▁B imm ot ob ot , ▁Mam at - ing ▁Sur , ▁Mam at - ing ▁Norte , ▁T ud ding an , ▁G using ▁Sur , ▁G using ▁Norte , ▁Bar ao as ▁Norte , ▁Dar am u ang an , ▁Dal - li pa o en , ▁Cab ar itan ▁Sur , ▁Ort iz , ▁N ativ idad , ▁Sug uid an ▁Norte ▁and ▁Sug uid an ▁Sur . ▁It ▁has ▁a ▁length ▁of ▁approximately ▁ ▁and ▁has ▁a ▁bas in ▁area ▁of ▁. ▁As ▁class ified ▁by ▁the ▁Environment al ▁Management ▁Bureau , ▁the ▁upper ▁reaches ▁of ▁the ▁river ▁falls ▁under ▁Class ▁A ▁which ▁means ▁that ▁it ▁is ▁suitable ▁as ▁water ▁supply ▁source ▁for ▁drink ing . ▁The ▁lower ▁reaches ▁has ▁lower ▁water ▁quality , ▁categor ized ▁under ▁Class ▁C . ▁ ▁The ▁other ▁major ▁stream ▁spr ings ▁from ▁the ▁Municip ality ▁of ▁Burg os ▁and ▁dra ins ▁the ▁valle ys ▁of ▁Bar ang ays ▁Agu io as , ▁S ili , ▁Al - al ina o ▁Norte , ▁N ags idor isan , ▁Ang in , ▁Sug uid an ▁Norte ▁and ▁N ativ idad