Colbun's seawater pumped-storage HPP project stalls over flawed EIS

A proposal for an innovative 800-MW pumped-storage hydropower plant (HPP) in the Antofagasta region, northern Chile, suffered a setback on Monday when a regional environmental assessment authority terminated its evaluation proceedings, citing critical omissions in the project’s impact study.

The environmental impact study (EIS) for the Paposo pumped-storage HPP project failed to include certain data on wildlife, overlooked several human communities and their activities, and inaccurately delineated the project’s area of influence, the Antofagasta regional authority said in Monday’s resolution to terminate further evaluation.

The Paposo project was developed by Chilean utility Colbun SA, which envisioned harnessing seawater from the Pacific Ocean to generate and store electricity utilising a two-reservoir system that takes advantage of a naturally occurring coastal cliff in the commune of Taltal.

The works would involve the construction of an on-site desalination plant, a lower reservoir, filled with the desalinated seawater and situated at the foot of the cliff, and an upper reservoir perched on the top of the cliff at 1,500 metres (4,921 ft) above sea level.

The whole scheme would represent an investment of around USD 1.4 billion (EUR 1.27bn).

After gathering observations from 16 regional entities, the environmental impact assessment authority for Antofagasta found that Colbun’s EIS was not up to standard. One of the consulted entities commented that Colbun did not inspect the highest part of the cliff face to detect the presence or absence of wildlife species, nesting sites or burrows. The utility considers that part of the hillside to be the area of influence for the wildlife, yet it did not carry out monitoring there, the resolution states.

But the biggest faults were found in the paragraphs of the EIS dealing with the environmental impact on human communities.

The Paposo project is sited close to eight indigenous communities, which Colbun identified as four belonging to the Chango nation and registered with the Chilean state, and four unregistered organisations dedicated to artisanal fishing and gathering who claim the Chango heritage. Indigenous communities within the area of influence perform their activities at places of cultural and historical significance less than five kilometres (3.11 miles) from the Paposo construction site, but Colbun claimed in the EIS that the project would not overlap with those locations. However, the company omitted information about the presence of two indigenous communities located about 500 metres (1,640 ft) from the construction site, which in turn affects the determination of the area of influence, according to the text of the resolution.

The resolution also states that three of the eight indigenous communities declared that the Paposo project would not affect their way of life and customs in any way. The remaining five groups asserted that construction, expected to last three and a half years, and the resulting infrastructure would limit their movement, obstruct their ability to collect coastal plants for medicinal uses and graze cattle.

Chilean regulations allow for EIS to be amended, expanded or its portions clarified during the evaluation proceedings. However, Colbun’s EIS was found to be lacking key information, which makes quantifying the environmental impact on wildlife and human groups difficult. Since there is no information, there is nothing to expand on or clarify, the environmental authority concluded.

Colbun has the option to appeal to the decision.

(USD 1.0 = EUR 0.907)

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