Mini Hydro Power Projects causing destruction!

While the controversy & stubborn decision making revolving around Upper Kothmale continues, there is a similar or much bigger yet unnoticeable issue developing within Sri Lanka’s Environment-for-Power policy.

True that we are a tropical country with a lot of rain, (not to mention the severe droughts that are on the increase) but does it justify our current practices of utilizing natural resources for the country’s so called never ending ‘Power Crisis’?

What is a ‘Mini Hydro Power Plant’ (MHPP)?

1. It’s relatively small in size & the amount of electricity generated. (usually a few Megawatts or a few hundred Kilowatts)
2. It users water to operate its turbines.
3. The water is brought down to the powerhouse from a little reservoir built above it. A big & long tube or tunnel is used for this purpose.
4. The little dam which stores the water is built across a stream or a small river. Hence, the flow of water is interrupted and re-routed through the tunnel or tube towards the turbines of the powerhouse.
5. Sometimes there are exceptions such as, the turbine/generator being situated within the tunnel itself. (Figure 2)

(Figure 1)

(Figure 2)

As you see the little contribution that the MHPPs make are only sufficient to fulfill the power needs of a few houses or a small village. That’s why you would normally find several MHPPs built in close proximity in a ‘chosen’ area.

So, what are the attributes of a ‘chosen’ area? These areas should have a considerable rain fall throughout the year with streams flowing with a sufficient amount of water. This means that these areas are more often than not rich in biodiversity and scenic beauty. Districts like Kegalle, Ratnapura, the Central province and a few other districts that experience a heavy annual rain fall are more often the candidates.

A dam built across a river may not appear to have a great impact in a rainy season, but when the dry season with less or no rain fall arrives, (at the moment it’s 3-4 months per year) what happens is that the stretch of the river from the dam to the water outlet goes dry. (See Figure 3) This leads to a river or stream with no water for that specific range and directly affects species fauna & flora, water springs and waterfalls.

(Figure 3)

Our experience has shown that this sort of ecological change takes place shortly after a few days of no rain in some areas where MHPPs have been built.

The construction, operation and management of MHPPs are done in several ways. In Kitulgala, we came across MHPPs which were built with aid from the Asian Development Bank. The maintenance is done privately while the people in the area must contribute a monthly levy for the maintenance of the MHPP and to payoff the debt received from these international monetary organizations as aid.

There is a different scenario in the Maliboda area in Deraniyagala where private companies are responsible for the construction and maintenance of MHPPs. They in turn sell/add the generated power to the main national grid while the government pays them back. These companies have found a large profit already by setting up MHPPs and destroying the forest in the process.

Some of the forest areas destroyed belongs to strict natural reserves as well. This is mainly done when constructing the dam, tube/tunnel and the powerhouse. Many beautiful waterfalls in and around Deraniyagala have already been threatened due to this behavior. Parties responsible for setting up MHPPs receive their required approval and consent through corrupted government officials and politicians in the area. They also make use of the ‘thirst’ of electricity the people in these areas face, hence misleading them of the dangerous long-term effects to come.

Long-term effects:

• Extended draughts.
• Landslides due to de-forestation.
• Extinction of rare/endemic fauna & flora.
• Drying out of springs & waterfalls.

An example of dangers caused to the environment is currently visible in Nekkawita/Deraniyagala, where a 10 MW (Megawatts) powerhouse is being constructed. A tunnel with a length of more than 1.5 km is being dug and a canal being constructed. Huge loads of earth have been dumped in the river where a dam is being constructed, making the river’s water brown and muddy, threatening its species. One wonders whether the 10 MW is worth the destruction being done to the environment.

If the volume of water is reduced as a long-term effect, no need to say that the productivity of these MHPPs would be greatly hampered and questioned in the future, making them worth nothing after all that destruction done to the ecosystem.

Clearly visible is the loose stance the government is taking and at times even promoting these projects so that they could wash their hands off it. Instead the government should take suitable & necessary measures in monitoring and approving these constructions while finding alternatives of providing electricity to the people in these areas.

Hopefully this sort of article enlightens many people who weren’t aware of it. Because though most of us enjoy the scenic beauty in our country, it’s only a handful that is aware of the dangers we face in protecting our environment for the future generation.


Image sources:
http://www.builditsolar.com