In April 2017, the Preliminary Environmental Impact Assessment (PEIA) for Project Lorena was approved, giving Amazonas Energía S.A.C. ( subsidiary of Andrade Gutierrez, Brazil) the green-light to move ahead a full EIA study (Resolucíón Directoral No 100 SENACE/DCA).
The Lorena Hydroelectric Project is the lowest altitude dam on the Marañón to gain approval so far. The 32m dam, located at 300m a.s.l would be inside Indigenous Awjun territory and interrupt access to habitat for up to 23 migratory fish species that inhabit this part of the Marañón River.
The question begs: Why is the Peruvian Government giving the greenlight to complete an EIA for this dam, when in October 2016 the Minister for Energy and Mining announced in Gestion newspaper that the government would not be building large dams in Amazonia?
The following are brief observations made by Marañón Waterkeeper on the PEIA for the Lorena Project:
- Area of Direct Influence is defined as the area that will be taken up by machinery and flooded by the dam, plus a buffer of 150m. It is noted that the human presence within this area is predominantly indigenous communities.
- The Area of Indirect Influence defined in this document extends less than 10km downstream of the dam wall. This is an enormous underestimation of the impact that this project will have on downstream ecosystems through changes in sediment load and impacts to migratory fish species. The indirect influence of this dam could easily extend several hundred kilometers downstream; impacting some of the most productive freshwater fisheries in Peru.
Defining the Areas of Influence in this way means that thousands of people downstream who may be impacted by this dam will be excluded from the consultation processes legally required to approve this project.
- No allowance or consideration has been made in this PEIA to allow migratory fishes to bypass the dam to reach their upstream habitat.
- Life expectancy of 100 years for a dam in this location is very optimistic. High sediment loads on the Marañón will cause the reservoir to fill up long before this life expectancy is reached. Sediments deposited in reservoirs may affect the safety of a dam without proper management (especially in seismically active zones). Large sediment loads will reduce lifespan of turbine components, and reduce storage capacity of the dam meaning it will not be able to operate as outlined in this PEIA.
- The ‘end of life plan’ is to leave the dam in place, full of sediment. Contrary to accepted norms, the PEIA states that it will not have any risk of instability or failure. Without proper monitoring and maintenance of the defunct dam, the risk of failure would hang over the heads of communities living downstream.
Currently in North America old dams are being removed to restore waterways, however the challenge is finding funding for this work. No dam should be constructed without a properly planned and funded end of life plan; in our opinion leaving a concrete monolith in place to interfere with native habitat, and cause risk to human life does not constitute an acceptable end of life plan.
- As outlined in the PEIA, Turbines will be operating at 50% capacity for approximately 6 months of the year due to lower inflows in the dry season. Therefore this dam will only have a potential of ~150MW for 6 months of the year, not including potential impacts of climate change which would further limit its capacity to generate power.
- The reservoir will be approximately 20km long, to create a fall of 32m and an installed potential of 300MW (150MW for half the year). This is a relatively small supply of energy which could be created elsewhere (wind being the most economical option, followed by solar and small hydro) without disrupting key migratory fish habitat, critical sediment flows and putting indigenous communities at risk.
In summary; this project will cause enormous environmental, social and cultural destruction for a paltry 300 (150) MW, energy that could easily be created using truly green energy sources. It is simply not worth the cost.
Ben, in addition to all of your comments on the PEIA noted above, I think their calculations of the Area of Direct Influence are flawed and vastly underestimated. It looks like the dam would be built at an elevation of 342 m and be up to a maximum of 50 m in height – yet the area of influence extends slightly higher than the known elevation at the upstream water quality station of 352m. Even if the water level or size of the dam was the proposed 32 m, the area of inundation would be to an elevation of 372m and extend much further upstream and horizontally in the valley. The math just doesn’t work out to me!
Also, the operational details are fuzzy to say the least. I don’t see anywhere the size and discharge of the turbines, yet everything seems to be based on a design of 200 cms (seems to be an annual average, not instantaneous). The reservoir flow through rates are likewise based on flows of 200 to 1200 cms but that also seems to be annual average. Are they proposing to run 200cms (or 1200 cms) through the turbines (spill the rest?)? The power production estimates seem to be calculated using average annual discharge but ignore instantaneous discharge which is what is available on a daily basis. A power engineer is needed to help determine if the “benefits” could actually be realized. Interesting that the hydrographs are missing so that one can see the amount of water actually in the river now. Perhaps they are in a different section of the report?
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