Water Resource Associates

Sabah Small Hydro Detailed Hydrological Study, Sabah, Malaysia, 2014-2015
[Nova Beta (M) Energy Sdn Bhd, Warisan Harta (Sabah) Sdn Bhd]. Hydrological analysis of rivers through application of GIS and catchment models across the State of Sabah to determine the potential yield for power generation and flood characteristics of the intake sites. The work involved analysis of rainfall, climatological and river gauging data, in conjunction with mapping of the river catchments, in order to provide simulated daily river discharge and estimated peak flood discharge at the proposed hydropower sites. The project aims to develop 432 MW of electricity from 17 small hydroelectric schemes at 11 sites across the State of Sabah. The HEP sites are located in six different river basins, with eight in the west and three in eastern Sabah, and at certain locations, power generation would be duplicated on the same reach of river.

Upper Karnali HEP Project Review Panel, Nepal 2014 –2015
Review the hydrology section of the existing Detailed Project Report, for this proposed 900 MW hydropower scheme in the far west of Nepal, for GMR Ltd, India. The water resources estimates were based on a 45 year record of daily flows. This record was found to be consistent, although the last few years possessed lower flows than the average. Some improvements to the flood estimates were recommended, using modern software, and increases to the PMF estimates, based on a previous report from the 1980s; The threat from breaches of upstream glacial lakes was found to be low, with no such lakes in the upstream catchment identified in Nepal, and the flood peaks from the 11 lakes identified in Tibet being sufficiently attenuated along the 260km of downstream river channel, to pose little threat.

Ogan River Study for Batu Raja Power Station, Sumatra, Indonesia, 2014
[Malakoff-Toyota-Hanson Energy]. Hydrology, water quality review and water supply feasibility study to use Ogan River water for cooling purposes in proposed new head-of-mine power station north of the town of Batu Raja.

Pelagus hydropower scheme hydrological study, Sarawak, Malaysia, 2012-2013
Hydrological analysis and catchment modelling for a proposed hydropower dam on the Rajang River at Pelagus Rapids in central Sarawak. [NorPower / Sarawak Energy Bhd]. The largest dam in SE Asia was completed in 2012 for the production of hydroelectric power at Bakun on the Rajang River. Other dams form part of the overall water resources development project on tributaries and further downstream of Bakun. This WRA commission provided the hydrology for the Inception and Concept phases of a proposed dam at the Pelagus Rapids downstream of Belaga.

Hydrological studies in support of hydropower development in Mozambique , 2007-2008
WRA were involved in a number of studies throughout Mozambique aimed at increasing hydro-electric power generation in the country during 2007 and 2008 for the Government of Mozambique, supporting Nippon-Koei, Norconsult and Atkins. One project focused on the expansion of power generation at Cahorra Bassa dam on the River Zambezi.

Temburong Transfer Scheme, Negara Brunei Darusalam, 2004
Review and Hydrological Analysis of potential dam sites in Temburong District for meeting public water supply requirements of 735 Mld by the year 2050 [MWH for Jabatan Kerja Raya, Negara Brunei Darusalam]. Hydrological study was carried out to assess the options and feasibility for construction of a new dam in the Temburong District of Brunei. The study comprised the review of the yield for various reservoir sizes and sites on the Batu Apoi and Temburong rivers in Eastern Brunei. This ambitious scheme will involve the transfer of water from the wetter and densely-forested part of Brunei, across Brunei Bay to centres of population in the Brunei-Muara District. The study also investigated the increasing severity of drought in Borneo and Brunei over the past 30 years, using 1936-2003 records.

Feasibility Study of Upper Tama Koshi Hydroelectric Project, Jan-Dec 2004
Hydrological studies of yield and flood frequency for run-of-river hydroelectric power scheme [Nepal Electricity Authority, NORAD (Norwegian Aid), NORCONSULT]. Water Resource Associates assisted the lead consultant Norconsult International by conducting the hydrology studies in this project. The scheme is located in the Dolakha district of central Nepal, and it is necessary to trek for two days from the nearest road-head at Singati Bajar to reach the project site, located close to the northern border with Tibet. The scheme will harness the Upper Tama Koshi river, which has a mean annual flow of 67 m3/s at the headworks, by means of a 7 km long head race tunnel, a 790 m fall of water through the penstock, an underground power house containing several Pelton wheel turbines, and a tailrace of 3 km. This high head scheme has the potential to produce 350 MW of power, to increase the current supply to Kathmandu and other industrial towns of Nepal.

Water Resources Management Plan and Power Systems Master Plan, Bhutan, 2001 - 2004
An updated and more comprehensive assessment of the country’s water resources development priorities, based on a decade’s collection of higher quality hydro-meteorological and sediment data. [Department of Power, Ministry of Trade & Industry, Royal Government of Bhutan]. The Norwegian Agency for Development Cooperation (NORAD). The original Power Systems Master Plan, prepared for Bhutan in 1990-93, identified the most promising 25 sites for future major hydropower schemes. During this 3 year period a network of 15 primary river gauging stations was constructed, and the Hydata software installed for storing and processing the hydrological field data collected. Water Resources Management Plan

Mangdechuu Hydroelectric Project, Trongsa, Bhutan 2001-2002
Hydrological studies of yield and probable maximum flood for run-of-river hydroelectric scheme. NORAD (Norwegian Aid), NORCONSULT. The scope included hydrological analyses undertaken for a major hydropower design study, including revision of rating curves, flow duration curves, low flow frequency, flood estimates at both the intake headworks and tailrace outlet, and examination of compensation flows in the river stretch downstream of the intake. Mangdechu is one of 4 schemes located in central Bhutan selected from the Hydropower Master Plan, which identified the most promising 25 potential sites for large hydropower schemes.

The viability of schemes has returned to the limelight, as government support increases for alternative energy sources and micro-power generation.

WRA has been involved in a number of projects involving the rehabilitation of hydraulic structures associated with mills. Over the past 20 years the debate around whether the production of electricity in this way is efficient, and how best to incorporate the power into the local grid continues to be a focal point. The viability of schemes has returned to the limelight, as government support increases for alternative energy sources and micro-power generation.

The service provided by WRA can be particularly helpful to owners and developers of new mini-hydro schemes associated with mills or weirs in the UK. There are three target activities in demand, which the Environment Agency would require to obtain the necessary approval of new schemes: hydrology, hydraulics and ecology. Such studies would examine the impact on flood characteristics of a site, and whether change in the fluvial regime would alter the ecological dynamics of the river in question. Consideration would need to be given to the hydraulic head and flow characteristics to determine viability, and WRA can provide expertise in dam safety and hydraulic design for refurbishment.

WRA’s clients include the Environment Agency, water companies, research agencies, foreign governments, industrial partners and the tourism industry.

Mill sites studied since 2003 include: Woolstone Mill [Oxon], Longwick Mill [Bucks], Bocking [Essex], Vilar das Almas [Portugal], Waterbury Mill, Horsted Keynes [Sussex].

WRA have experience of mini-hydropower in the following countries: Angola, Mozambique, Portugal, Nepal, Bhutan, Malaysia, Uganda, Pakistan, Cote d'Ivoire, Mauritius, China

WRA maintains a partnership with small specialist businesses which have particular specialism within the field of hydrology, in particular with Wallingford HydroSolutions [WHS] and Oxford Scientific Services. WHS is now the distributor of LowFlows2000, which is relevant software for estimating the flow duration curve at ungauged sites. This service would also be considered for the hydropower studies, depending on the availability of actual streamflow data.