﻿BAGUIO MINERAL DISTRICT. 215 



DRAINAGE. 



Although the Agno, the largest river of the Province of Benguet, is 

 beyond the border of the district to the east, it has an important bearing 

 on the drainage. The headwaters of this river are on the eastern flank 

 of Mount Data, the divide between southern Lepanto and northeastern 

 Benguet, and in its passage south to the plains of Pangasinan it gathers 

 the run off from the western slopes of the main mountain range, the Cor- 

 dillera Central, the backbone of Luzon, and the eastern slopes of the 

 smaller range and ridge which forks southwesterly from Data and termi- 

 nates at Santo Tomas, forming the Benguet highland. Therefore, it 

 gathers meteoric waters over a comparatively large area, and erosion by 

 it and its tributaries has been considerable. All the drainage from the 

 eastern half of the Baguio district feeds into one branch, the Itogon. 



The Antamok River drains the smaller valley east of the Pakdal-Itogon 

 Bidge; it is quite dissimilar to the rest of the drainage in that it pos- 

 sesses no tributaries of any magnitude. Although the valley has been 

 deeply incised, no lateral streams have kept pace with it within the map 

 limits. At its headwaters east of Pakdal there is more or less of a basin 

 of auxiliary drainage; at Bua, one small western branch is developed, 

 and east of Antamok a somewhat larger branch to the north has cut 

 into the eastern wall of the valley, but erosion has generally been confined 

 to the main valley. Some rough measurements on the Antamok in the 

 dry season gave the quantity of water flowing as 1,200 cubic feet per 

 minute, or 20 second-feet. Power is being taken from the river at this 

 point for use in a stamp-mill and developed by pipe line and impulse 

 wheel. 



A short distance below Antamok, the Antamok River joins the Itogon, 

 of which it is a lateral tributary. The Itogon drains the area from the 

 Pakdal-Itogon Ridge to the Kias Ridge, through several good-sized 

 streams and through the Sile or Gold Creek, the Batwaan and many 

 smaller streams. Gold Creek has the larger territory, heading in the 

 eastern and southern sides of the Baguio Plateau and reaching the Kias 

 Ridge with its eastern branches. Its volume normally is greater than 

 that of the Antamok, and throughout its area the lateral branches have 

 kept pace with the erosion of the main channel, cutting a well-defined 

 basin between the Kias and the Pakdal-Itogon Ridges. 



The Batuaan heads in the southern end of the Kias Eidge and again 

 resembles the Antamok in its clean-cut valley with little lateral extension. 

 The system described above constitutes the drainage of the larger and 

 eastern part of the Baguio district. 



The Baguio Plateau is drained to the north and west directly to the 

 China Sea, via the Irisan and Trinidad Bivers, which in the Baguio 

 district proper are mere creeks, cutting slight valleys m the plateau. 



