(a) Commencing from Kuala Rajang at Tanjung Selalang at position Latitude 02° 05.7' N Longitude 111° 0 12.4' E; then following a line across to Kampung Jerijeh at position Latitude 02°0 08.35' N Longitude 111°010.9' E; to upstream.
(b) Commencing from Kuala Belawai at position Latitude 02°12.1' N Longitude 111° 11.37' E; then following a line across to Tanjung Manat at position Latitude 02° 13.95' N Longitude 111°0 11.25' E; to upstream.
(c) Commencing from Kuala Paloh at Tanjung Pasir at position Latitude 02° 26.34' N Longitude 111° 15.07' E; then following a line across to a position at Latitude 02° 26' N Longitude 111° 17.8' E; to upstream.
(d) Commencing from Muara Lassa position Latitude 02° 42.5' Longitude 111° 22.65' E; following a line across to a position Latitude 02° 41.9' N Longitude 111° 25.75' E; to upstream.
(e) Commencing from Kuala Igan at a position Latitude 02° 50.3' N Longitude 111° 39.1' E; then following a line across to Tanjung Duga at position Latitude 02° 50.3' N Longitude 111° 40.22' E; to upstream. (All the river mouths mentioned above confluenced to Batang Rejang.)