This section utilises two strongly simplified socio-environmental indicators for the existing and planned hydropower projects in the Nam Ngum basin. It is based on the notion commonly used in the industry that for screening/scoping purposes one can calculate efficiency indicators for different projects. These values agree with basic life-cycle assessment (LCA) principles in that one assumes a measure of damage per unit of produced economic good. The data we base ourselves on is sourced from the Department of Electricity’s Hydropower Office and available IEEs/EIAs/EMPs for the concerned projects.
It is of the utmost importance to stress that these indicators are not the result of an assessment of the suitability and/or sustainability of the individual projects, but just strongly simplified indicators.
3.3.1 Indicators
The two indicators used here are two different ways of measuring efficiency – one relating the installed capacity to the project’s land take and the other relating the number of resettled people to the generated energy in the project. The object is to relate the damage caused by the project to the economic good produced by it. It is a very sensible, but coarse, approach to
comparing different projects. Sensible because it focuses on the effectiveness of the project (not just income or generated energy). Coarse because it is a very simple quantitative tool, completely lacking in qualitative considerations which, at individual project level, are absolutely necessary in order to establish the feasibility and necessary mitigation etc., for a hydropower project. One example could be where project A floods half as much area as project B, but prime paddy-rice land, rather than poor thin upland soils, making the lower land loss in project A (expressed as km2), a more serious one than that in project B. Another example is when one hydropower project which is located in a previously pristine river (e.g.
Nam Lik 2) is compared to another one located in an already strongly altered river (e.g. NN3 and NN5). The latter is clearly to be preferred from a socio-environmental point of view.
We have chosen to include a list here for two reasons: 1) it is a priority for a strategic environmental study to provide indicators that constitute a basis for decision-making; and 2) the concept of power density is very frequently used these days, following its adoption within the rules and regulations for the Clean Development Mechanism (CDM) of the Kyoto Protocol. The power densities of 4 and 10 W/m2 are important for the treatment of hydropower projects in the CDM. The other indicator, more socio-economic in nature, is a resettlement index, relating the number of people who have to move to the average annual generation of energy.
The power density (W/m2) is obviously better the higher the score. The opposite is true with the resettlement index – the higher the score, the worse the specific impact. From a methodological point of view it would be good to have the indicators “move the same way”, but since division with 0 is not possible, the resettlement index has to be people/GWh, and the power density index is so established that we choose not to change it.
3.3.2 Results
The information presented in Table 3.3.1 below suffers from some rather important gaps. We have, however, chosen to include as many relevant parameters (reservoir area, land take from roads, other land take, total land take, number of resettled people, and installed capacity and average annual generation of the plant), as possible, and calculated indicators based on incomplete data. The resulting indicators are presented in Table 3.3.2. All project figures are exclusive of land take for transmission lines. The reasons for this are that; 1) many projects will ultimately share right-of-ways for their lines, making individual assignment of land take area very difficult; and 2) transmission-line right-of-ways are normally not exclusive from a land use point of view. This will not affect the general tendencies in the results.
Table 3.3.1: Basic project data for some Nam Ngum hydropower projects Project Reservoir
(km2)
Resettlement (people)
Installed capacity (MW)
Generation (GWh)
NN11 371 3 200 155 966
NN2 122 5 900 615 2 310
NN3 26 5003 440 2 000
NN5 15 400 100 420
Nam Lik 12 25 2 400 60 250
Nam Lik 22 42 0 100 353
Nam Bak 12 9.2 0 115 607
Nam Bak 22 7.5 0 68 365
1)Including the Nam Xong diversion dam 2) Studies ongoing, data might change
3) People will only be resettled within existing village boundaries Data from various sources: DoE; feasibility studies; EIAs; Norplan 2004
Table 3.3.2: Two simple indicators for the hydropower projects in our study (with two significant digits)
Indicator NN1 NN2 NN3 NN5 NL1 NL2 NB1 NB2
W/m2 0.42 5.0 17 6.7 2.4 2.4 12 9.1
People/GWh 3.3 2.6 0.25 1.0 9.6 0 0 0
The uncertainties in the basic data are, however, many. Also the very doubtful figure on resettlement in Nam Lik 1, which is a low estimate based on the number of affected houses (630) identified in the IEE (SNC Lavalin, 2007).
The results are very mixed, as could be expected. It should be borne in mind that hydropower plants with good scores in these types of indexes often score well thanks partly to other power plants scoring poorly. If one plant high up in a catchment has a very large reservoir, it is feasible to develop a number of run-of-river (or at least with very small intake ponds) plants downstream which will then score undeservedly well in both the indexes used here. Hence it is often most useful to assess hydropower impacts and efficiency on a catchment basis. If we add up the numbers for the stations planned or under construction (the ones in the table above, minus NN1), the resulting numbers on the Nam Ngum mainstream (NN2, NN3, NN5, Nam Bak 1and 2) is 7.4 W/m2 and just over 1 persons/GWh. For the Nam Lik branch, the same numbers are 2.4 W/m2 and approximately 4 persons/GWh. The numbers for the Nam Ngum mainstream are reasonable from an international perspective, the ones for Nam Lik are quite poor, especially if the resettlement figure for Nam Lik 1 is not exaggerated. It is also clear that the NN3 project scores the best, together with Nam Bak 1.
At this level of (lack of) analytical detail it is clear that the Nam Lik projects are not favourable from a socio-environmental efficiency point of view. It is also worth pointing out that an alternative configuration of the NN2 and NN3 projects described in e.g. the Power System Development Plan by Maunsell and Lahmeyer (2004), would have made the scores for the Nam Ngum branch considerably better. On the basis of these indicators it can be concluded that the design changes brought about between 2004 and 2007, increasing installed capacity considerably in NN2 and decreasing it in NN3, thereby increasing the total flooded land area considerably, have not been socio-environmentally optimal. With clear strategic guidance and IWRM principles taken into consideration, it is likely that the configuration presented in the Power System Development Plan would have been kept, instead of that now implemented.
4 Development Scenarios and Impact Zones