Socio-economic and Environmental Impacts of MHP

Compared to large hydropower projects, micro hydropower schemes have relatively low negative environmental and socio-economic impacts. As recent evaluation studies on MHP projects and the along going electricity supply suggest, particularly socio-economic impacts of the plants are to be considered positive. Just like other off-grid renewable energy applications, MHP schemes have a variety of direct and indirect positive impacts, which are often interrelated.

Positive socio-economic impacts

Electricity supplied by MHP enhances income generation (agro-processing and small service business such as mills and shops) and enables inhabitants to make savings on expenses on kerosene, gasoline, candles and batteries. Income increase and savings as well as the possibility to use refrigeration improve the diet and thus decrease malnutrition and hunger. Moreover, women’s and children’s work load decreases, since they spend less time on energy related household tasks such as the collection of fire wood and water gathering. As mentioned above, that does not only reduce physical impairments resulting from the heavy loads, but also reduces the risk of harassment and sexual assault and thus HIV/AIDS risk. The communities’ safety in general improves due to street lighting at night. Furthermore women and children have more productive time which can be used for studying and thus education is improved. Electricity supply allows lighting at night and gives inhabitants the chance to study during evening hours. Latter also improves the communities’ social life, since community gatherings at night are possible and it benefits from electrical devices such as TV and radio. Furthermore telecommunication is enhanced. People get more aware of the outside world which gives them more knowledge. The electricity provided by the MHP has a positive impact on the communities’ health situation, since it decreases indoor air pollution and the risk of fire. Moreover it allows the use of refrigerators for medicine (keyword: vaccination) and groundwater pumps. Latter reduce water borne diseases due to contaminated surface water. Due to the enhanced technical equipment, more doctors and teachers are attracted to the mostly remote areas, which further improve health and education services.

Positive environmental impacts

In environmental terms, the MHP project raises the awareness of proper watershed management and reforestation to secure the sustainable use of water resources. Moreover the plants contribute to protect the environment and combat climate change through reduced use of kerosene/gasoline and small batteries. Generally it should be noted that impacts not only depend on the MHP itself, but also on what training and campaigns go along with its implementation and in what way the communities tap the full potential of the electricity supply.

Negative environmental impacts

Since no large reservoirs are required, no resettlement programs and the along going negative impacts for the population occur. Nonetheless some scientist argue that particularly the environmental impacts of small-scale hydropower, when widely used, would be no less serious per kW generated than those from large scale hydropower plants. The impacts of hydropower schemes depend on the way they are designed. Since MHP and PHP schemes do not require a reservoir and divert only part of the stream water away from a portion of the river to power the turbine, they only have little impact on the flora and fauna of the vicinity. However they tend to create small, shallow pools which can cause problems such as sedimentation as well as eutrophication and can thus affect water quality and lead to greenhouse gas emission. Particularly a decrease of water quality can furthermore cause water borne diseases and thus affect the health situation of the population. Moreover aquatic species can be affected negatively in terms of migration and change of habitat condition. Due to the MHP and the along going electricity supply, a population growth close to the powerhouse is likely to occur. Thus the pressure on natural resources and the risk of erosion in areas close to the powerhouse is increased. The increased degradation rate can lead to an increase of sediment load of the river as well as to a reduction of the soil’s retention capacity, which can in turn result in an alternation of the discharge rate, showing in longer dry periods and an increased risk of flash floods. Consequences might be that a sustainable use of the MHP cannot be provided. Further environmental impacts might be deforestation due to the construction of access roads and grid connection power lines.

Environmental vs. socio-economic benefits

It should be noted, that some features might be considered positive in socio-economic terms but negative in environmental terms and vice versa. Taking the construction of access roads as an example, it has negative impacts on the environment since increased deforestation occurs but positive socio-economic effects in terms of increased access to the market and (in some areas) increased income from tourism. When constructing an MHP scheme, it is thus of great importance to be aware of complex interdependencies between positive as well as negative environmental and socio-economic impacts and benefits which can vary between population groups in terms of income and location of their households. It should be deliberated on whether the benefit of the MHP implementation exceeds possibly occurring negative impacts, taking into account environmental as well as socio-economic features. The schemes’ impacts on the health situation can be taken as an example: the plants’ environmental impacts such as decreased water quality might affect population’s health, nonetheless the electricity supply might also improve the overall health situation due to refrigeration, improved access and increased income to purchase medicine. Generally, negative impacts should be kept to a minimum by incorporating and implementing respective mitigation techniques already in the planning and construction phase of the MHP project.