E1491 v 4 Western Provinces Rural Water Supply, Sanitation and Hygiene Promotion Project (World Bank / DFID) Public Disclosure Authorized Sichuan Province ABSTRACT OF DAM SAFETY IN 20 PERCENT OF PROJECT AREAS Public Disclosure Authorized Southwest Jiaotong University Public Disclosure Authorized Nov.2006 Public Disclosure Authorized Contents 1 Brief Introduction to the Project ..............................................................................1 2 Basic Information of the Dams in 20 Percent of Project Areas.................................1 3 Description of Dam Safety ......................................................................................4 3.1 Safety of the Dams Already Appraised .........................................................4 3.2 Analysis of the Safety Appraisal Results of the Dams...................................6 4 The Counter-measures for Safety Problems of the Dams .........................................6 5 Proposals Concerning the Safety Management of the Dams...................................12 5.1 Requirements for the Dams yet to be Appraised..........................................12 5.2 Requirements for Dams Already Appraised ................................................14 5.3 Monitoring of Dam Safety ..........................................................................16 5.4 Fund Sources for Dam Safety Management ................................................17 6 Conclusion and Suggestions..................................................................................17 Accessory 1 Master List of All the Dams……………………………………………….18 Accessory 2 Dam Safety Review Guidelines…………………………………………19 Accessory 3 Emergency Preparedness Plan…………………………...……………...39 Abstract of Dam Safety in 20 Percent of Project Areas World Bank & UK Government funded WPRWSSH Project, Sichuan Province. 1 Brief Introduction to the Project The water supply project engineering includes centralized water supply, cluster of households’ water supply and individual household water supply which are carried out in all project counties, with the centralized water supply engineering being carried out at 247 sites in 123 townships of 10 counties, involving 28 reservoirs of which 12 reservoirs have dams higher than 15 m. 2 Basic Information of the dams in 20 Percent of Project Areas Within the 20% project area, Renshou County of Meishan City, Jialing District of Nanchong City do not have reservoirs for centralized water supply engineering, but Lezhi County and Pingchang County have, according to the on-the-spot investigation and data analysis. Eight reservoir dams in the 20% project area are involved in the project, with four reservoir dams at Lezhi County and the other four at Pingchang County. By reference to the classification prescribed in “World Bank Operational Policy: Safety of Dams”, five out of the eight reservoirs have dams higher than 15 metersthree out of the eight reservoirs have dams lower than 15 m. Table2-1 shows the basic information about the eight dams and Table2-2 shows the basic information about the five dams higher than 15 m, based on the investigation and data collection and analysis. Southwest Jiaotong University 1 Abstract of Dam Safety in 20 Percent of Project Areas World Bank & UK Government funded WPRWSSH Project, Sichuan Province. Table2-1: Engineering Data of Eight Dams in the Water Supply Works Total Rain Reservoir Benefi Gather Dam Project Belonging in Reservo Capacity Dam Reservoir ciaries ing Heigh County which ir Type (10 Type Name (persons) Area t (m) Project thousan km2 m3) Taiji centralized Small Earth Bajiaomiao 2610 19.8 975 23 water supply (1) dam works Baojianhe Homogen centralized Small Baojianhe 10390 9.63 50.4 ous earth 7 water supply 2 dam works Lezhi Yanjinhan Homogen centralized Small Yanjinhan 1365 17.6 223 ous earth 14 water supply (1) dam works Chachahe Stone centralized Small Chachahe 17319 94.5 350.2 oblique 12 water supply (1) wall dam works Yankou Clay Zhuangzi Small Changyan 2562 2.30 139.0 oblique 30.33 water supply (1) wall dam works Lancao Homogen Xinmin Small Xinmin 3366 1.15 11.20 ous earth 27.48 water supply (2) dam works Pingch ang Yuntai Earth- Shengli Small stone Lihua 1443 2.62 135.0 31.30 water supply (1) mixed works dam Sima Plasm Shangyou Hill lined Panqiaogou 2321 0.8 1.8 16.5 water supply pond stone works arch dam Southwest Jiaotong University 2 Abstract of Dam Safety in 20 Percent of Project Areas World Bank & UK Government funded WPRWSSH Project, Sichuan Province. Table2-2: Engineering data of dams higher than 15 m in the water supply works Total Ben Rain Reservoir eficiari Dam County Belonging in Reservoir Gather Capacity Dam Reservoir es Height Name which type ing (10 Type name (perso (m) project Area thousan n) km2 m3) Taiji centralized Lezhi Bajiaomiao Small (1) 2610 19.8 975 Earth dam 23 water supply works Yankou Clay Zhuangzi Changyan Small (1) 2562 2.30 139.0 oblique 30.33 water supply wall dam works Lancao Homogeno Xinmin Xinmin Small (2) 3366 1.15 11.20 us earth 27.48 water supply dam works Pingch ang Yuntai Earth- Shengli Lihua Small (1) 1443 2.62 135.0 stone 31.30 water supply mixed dam works Sima Plasm Shangyou Panqiaogou Hill pond 2321 0.8 1.8 lined stone 16.5 water supply arch dam works Southwest Jiaotong University 3 Abstract of Dam Safety in 20 Percent of Project Areas World Bank & UK Government funded WPRWSSH Project, Sichuan Province. 3 Description of Dam Safety 3.1 Safety of the Dams Already Appraised Of the eight reservoir dams involved in the 20 percent project area, seven reservoirs have undergone safety appraisal in compliance with Safety Management Regulations for Reservoir Dams of the PRC. The remaining one, Bianqiaogou hill pond, hasn’t been appraised for the reason of the disagreement between the domestic requirement and the World Bank requirement (domestic requirement being that safety appraisal will be carried out for those reservoirs with a capacity of over 100 thousand m3, while the World Bank’s being that safety appraisal must carried out for dams higher than 15m) See table 3-1 for the appraisal results. Southwest Jiaotong University 4 Abstract of Dam Safety in 20 Percent of Project Areas World Bank & UK Government funded WPRWSSH Project, Sichuan Province. Table3-1 Results of Reservoir Dams Safety Appraisal Safety Apprai Safety County Belonging to Remarks Project Names sal Class which reservoir Report Bajiaomiao centralized Bajiaomiao Yes Class II water supply Baojianhe centralized Baojianhe Yes Class II Two Grade 2 water supply Lezhi Dams, Two Yanjinhan centralized Yanjinhan Yes Class Grade 3 Dams. water supply Chachahe centralized Chachahe Yes Class water supply Three Grade 1 Lancao Xinmin water Xinmin Yes Class I Dams. Besides, supply works as the capacity of Banqiaogou Reservoir is less Yuntai Shengli water Lihua Yes Class I than 100 supply works thousand M3, as such the safety Sima Upstream Water Banqiaogou Hill appraisal is not No / Supply Works Pond necessary Pingchang according to domestic requirement. But as its dam is higher than 15m, Zhuangzi Water Supply Changyan Yes Class I the safety Works, Yankou appraised is needed according to the World Bank requirements. Southwest Jiaotong University 5 Abstract of Dam Safety in 20 Percent of Project Areas World Bank & UK Government funded WPRWSSH Project, Sichuan Province. As is shown in the above table, there are three Grade 1 dams, two grade 2 damstwo grade 3 dams and one dam yet to be appraised. 3.2 Analysis of the Safety Appraisal Results of the Dams According to the “Safety Management Regulation for Reservoir Dams of the PRC” dams can be classified into: Grade 1 Dams: refers to those dams, in normal operational conditions, without grave engineering quality problems, whose flood resistance capacity meets the Ministry’s criteria, and functions as it was designed. Grade 2 Dams: refers to those dams, in normal operational conditions, without grave engineering quality problems, whose actual flood resistance capacity falls no short of the special criteria issued by the Ministry for the key water conservancy projects with dangers recently removed and the structure strengthened, and functions as it was designed. Grade 3 Dams: refers to those dams whose actual flood resistance capacity falls short of the special criteria issued by the Ministry for the key water conservancy projects even with dangers recently removed and the structure strengthened, or the project has some grave engineering quality problems which have affects on the safety of the dam, and can not function as designed. The three grade 1 dams involved in the project do not have grave safety problems. No special reform measures are needed except for some replenishment of observation facilities and continuity in regular management. The two grade 2 dams and the two grade 3 dams have problems of seepage, aging or white ants problems, and have inadequate observation and management facilities. Prompt renovation measures and funds are needed for such dams to ensure the safe operation. With Banqiaogou Reservoir, the safety appraisal will be done promptly by the relevant department. 4 The Counter-measures for the Safety Problems of the Dams Different measures will be applied according to the types of the dams. With the three grade 1 dams, it is necessary, of course, to strain the regular management and monitoring. Southwest Jiaotong University 6 Abstract of Dam Safety in 20 Percent of Project Areas World Bank & UK Government funded WPRWSSH Project, Sichuan Province. With the Banqiaotou and Bajiaomiao