Water diversions in the lower Mekong basin current status and issues Mekong river basin Nguyen Nhan QUANG River Basin Management expert 1 2 Longitudinal Profile of Mekong from source to sea Brief on the water uses of lower Mekong basin countries Thailand: According to the 10 th (2005-2010) and 11 th (2011-2016 with vision up to 2027), national socio-economical development plans, E-sarn region is oriented to become a centre for producing and processing food, foodstuff, biofuel and tourism development of whole country. New construction and improvement of irrigation and drainage systems, large-scale water diversion 3 4 - Thailand has biggest number of irrigation structures (6,388) and Vietnam is the second in irrigated area (after Viet Nam), - Irrigation projects are mainly located along river corridor and flooded plains in the NE and around larger reservoirs and small weirs, - Constraints for cultivation in dry season are mainly caused by salted soils, high level of underground water table, limitation of surface water resources in tributaries where watering requires for high-head pumping, - Thailand plans to consider more 990 projects in NE that are mainly water diversions/pumping from the Mekong, 5 - In dry season of 2015-2016, according to Royal Irrigation Department RID, water volume of four large dams (Bhumibol, Sirikit, Pa Sak Jolasid, Khwae Noi Bamrung Daen) was 3,726 km3, sufficient for meeting demand, - There are 548 districts (= 59% of total 978 districts) suffer from water shortage, - RID applied a measure to release water from main dams until May 2016, and dig wells in some districts, - National Water Resources Committee considered 15 projects of which there are some intra- and inter-basin diversions ones (e,g,yuam -> Bhumibol reservoir),,,, 6 1
Cambodia: 75% out of 3,7 million ha is rice cultivated area, Cambodia has been being a rice-exported country (1,2 million tons in 2013) In most areas, rain-fed irrigation is main method, Cambodia is, in cooperation of externals (mainly Chinese), building new head works and canal systems almost of that are located inside the Mekong basin At present, irrigated areas are 504,245 ha, Irrigated areas will be expanded to 772,499 ha in 2030 and new system will be built for 6,000 ha Lao PDR: - Irrigated areas are mainly narrow trips and located along tributaries and flooded plains along the Mekong mainstream, - Irrigated areas is currently 166,476 ha - According to development scenario, about additional area of 213,062 ha will be expanded by 2030 and some new irrigation projects are proposed for area of 238,617 ha 7 8 Viet Nam: - At present, annual irrigated area is about 1,92 million ha (accounting for 48% total irrigated land in the lower Mekong basin), - According to development scenario up to 2030, about 339 small scale irrigation projects in Se San, Sre-pok basins with increased area of 125,165 ha will be added, Irrigation system in the Mekong delta - In the Mekong delta, it is proposed to not expand irrigated areas (limits of land, salinity intrusion,...) 9 10 Country Irrigation projects (current and proposed, both expansion and newly built) Number of projects Current Irrigated area (ha) Scenario to 2030 (expansion) Irrigated area (ha) Scenario to 2030 (newly built) Number of projects Irrigated area (ha) Cambodia 2,091 504,245 772,499 32 6,000 Lào 2,333 166,476 213,062 2,768 238,617 Thái Lan 6,388 1,411,807 1,411,807 990 984,904 Some water diversion projects in Thailand Two types: - Inter-basin diversion: from Mekong to Chao Phraya basin including options of Kong-Ing-Yom, Kok-Ing-Nan; Kong-Pasak,... - Intra-basin diversion (inside Mekong basin): from left (Lao side) to right bank (Thai side), from Mekong mainstream on right bank (Thai side) diverted into far inland with various routes (within Thai territory) Việt Nam 606 1,919,623 1,919,623 339 125,165 11 12 2
Water diversion (interand Intra-basin) options 13 14 Intra-basin diversions (in North East region): Water diversion from Huai Luang into Song Khran, that had been ceased due to people s protection. Intra-Mekong basin diversion in North East region of Thailand Project to purchase water from Nam Ngum reservoir of Laos JICA has stopped the study though conducted since 2007. Then Korea, a successive country also ceased to study Thailand is undertaking studying and constructing monkey cheek reservoir on the Mekong tributaries, to take and store water diverted from the Mekong mainstream. Some water diversion/taking projects: 15 16 Mekong river Mekong-Huai Luang-Nong Han-Lam Pao diversion Loei river Huai Luang river Chi river Mun river 30 reservoirs are built to store water diverted from Mekong river and irrigate for the areas around these reservoirs, Stage I including Nong Han reservoir was completed. A plan to deepen and enlarge the reservoir up to 28.124 Mio. Rai (=45 km2) is considered. When the embankments around the reservoir is heightened, annual in- and out-water volume is 2.8 km3 During three months of dry season 2016, pumped volume was 40-47 Mio. m3 to Huai Luang. This figure will be increased to 100 Mio. in 2017, 17 18 3
Four movable pumps to take water from Mekong mainstream Huai Luang river in May 2016 19 To pump water and fill in a middle reach 20 Gated sluice with pumps (left side) for pumping water to upstream of sluice Fish ladder on the right side of sluice Pumps were in operation (pumped water from Mekong) 21 22 Diversion via Huai Luang - Lam Pao - Chi Water for irrigation or tourism? 23 24 4
01/06/2017 Kong-Loei-Chi-Mun water diversion: Map of Kong-LoeiChi-Mun water diversion Under preparation phase that consists of nine steps. Step 1 undertook in period of 450 days (9 Oct. 2015 to 31 Dec.2016). Details of components: - A head-work on Loei river (2.29 km from confluence with Mekong) - Open canal with dimension of 250 x 450 x 5-7m) - Tunnel consisting of 24 pipes of 10 m diameter and divided into two branches for diverting water to Huai Luang (54.45 km) and Ubolratana (85.563 km). - Futher open canal for diverting water to irrigated areas in Chi and Mun basin 25 Srisongrak headwork 26 Length of total canals is over 2.210 km, running through 17 provinces and 113 districts in NE. Water is gravity diverted thanks to different of elevations: intake at+ 192-195 m, dam at+ 182 185 m. Water discharge to be diverted from Loei river (close to Mekong river) varies between 138 147 m3/s (or in volume: 2. 025 2.036 km3/year). Investment costs: 130-159 billion Baht (3.72 4.55 billion USD) Costs for pumping: 60-550 Mio. Baht/năm (18-16 Mio. USD/year) 27 Kong-Loei-Chi-Mun headwork & tunnel 28 Elevation differences at various location Thai Puon don t want to have Srisongrak 29 30 5
Cambodia: Vaico Irrigation Project includes two phases with total costs of 200 Mio. $ Phase I (2012 2017) consists main components: - A sluice/dam (site closes to PhumDom Nak Prean) to take water during flood season from Samdei river. Dam has two regulated gates. Bottom elevation of dam is + 5.5 m. Maximum water level to be diverted through sluice is at +13.5 m - An intake canal to divert water to Krapik lake/reservoir (estimated volume is 100 Mio. m3) - Canal system includes a primary canal from the lake, and secondary canals to Kongpong Cham, Preyveng, Sveyreng, along and across of that, there are several dams to divide the primary canal in several sections for storing water - Small sluices are built along two sides of the canal 31 32 Intake canal to divert water from dam to Pradik lake/reservoir Dam/sluice to take water from Samdei river Secondary canal 33 34 Some remarks: - The more water to be diverted in the upstream part, the more concern relating to negative impacts to the Mekong delta (it is necessary to undertake overall evaluation of cumulative impacts caused by hydropower projects, inter-basin diversions, others...) - If water is diverted in wet season, moderate flood (lũ đẹp) in the Delta is difficult to appear. - Should the so-called increment of low flows in dry season presumelly resulted from hydropower regulation on mainstream be feasible, if majority of the increased volume will be diverted and stored in increasing monkey cheeks - In fact, from 9 March to 31 May 2016, China three times released more water downstream, bur data observed showed that, flows in middle reach in Laos were noworthly increased Water level at Chiang Saen in dry season 2015-2016 35 36 6
Remarks (cont d.): - Water diversion is took place in wet or dry season? (or in transition period?) - Water use in Vai Co project is in basin or interbasin diversion? The above remarks relate to compliance with the 1995 Mekong Agreement and procedures thereof, especially requirements for notification and consultation on the proposed projects (in timely, sufficiently and transparent manner). Water level at Vientiane in dry season 2015-2016 37 - Access to available information is still difficult. - Role of the MRC member countries and Secretariat in actively position to obtain relevant information. 38 What to do? - From various channels, relevant information need to be collected that would facilitate the analysis on the impacts of various water uses in the Mekong basin - Role of NGOs, CSOs in providing the fact on and real picture of water use situation in the region and more importantly raising the public voice as well as voice of local community whose livelihood will be impacted by various interventions. - Relevant agencies involved in the Mekong cooperation need to, on one hand comply with the commitments, and on the other hand, look into other possible options including newly set-up mechanisms for mutual benefits and mutual bearing responsibility in Mekong... 39 Thank you for your attention 40 7