Philippines - Additional Financing for Rural Power Project : environmental assessment (Vol. 3 of 8) : Colasi river mini hydro plant, comprehensive feasibility study

E1992 v3 THRO~JGHTHE INITIATIVEOF MAYORREPITOPAJARILLO LO ANL) THE SANGGUNIIANG BAYAIV Of: MERCEDES  The site was initially visited on 26 Septernbcr 2003 aid then severa! reconnaissance trips and detailed surveys were untiertaken lasting up to 15 Novernber2003. 1.4 PROJECT LOCATION AND RELATIVE DISTANCES 1.4.1 General The Colasi river, where a proposed mini-hydro power systern will be situated, is located about forty (40) kilometers southeast (SE) of Daet, the capitol town of the Province of Camarines Norte. Figure 1-1 shows the locationmap. 1.4.2 Specific Eocation of Primary Scheme The proposed project site is located w i t b the political boundq of Mercedes Municipality. The proposed diversion dam is situated at 13' 55' 12' latitude and 123"03' 04' longitude. Similarly, the power plant site is located at 13' 03' 37' latitude and 123" 50' 49' longitude  FIGURE 1-1 PROJECT LOCATION MAP  CHAPTER 4.0: WATER RESOURCES 4.1 WATER SOURCE DESCRIPTION The mini-hydro site is located at the upper reaches of the Colasi river draining the west-east slope of Colasi mountains. The mini-hydro site is situated on a mountainous area. The watershed cover consisting of relatively thick second growth forest trees and undergrowtfis is classified as generally in good hydrologic condition. Srnail expanses of relatively flat grounds are pianted to upland rice, com and vegetab1es. The river and tributary system is classified under youthful development stage. The channels are characterized with tlie presence of deep v-shaped valleys, steep slopes,rapids and waterfalls. The delineation of the watershed area is shown figure 4-1 based on a best weir location of Elev. 280 rneters (rn) above mean sea level. On the bas~s.of this level, the calculateddrainage area is: WATERSHED AREA =9.3 Km2 Page 4-1  4.2 hlYDRQMETEOROLBGICALCHARACTETUSTICS The area falls under type II climate. This climate type is characterized by no district seasons with very pronounced maximwn rainfall fkom October to J a n u v and no dry season. Nomally under ths type, r d a l l is fairly well distributed throughout the year The following is a s m a q of climactic conditions at the proje