It took a while, but the government of Nicaragua finally released the Environmental and Social Impact Assessment (ESIA) for the proposed Nicaragua Canal megaproject. It can be downloaded here. The ESIA was handed over to the government back in early June, a few months after a group of us reviewed parts of the environmental studies at FIU in March. It wasn't clear why the government was waiting so long to release the ESIA, though back in September the government announced that construction would be delayed in order to conduct further studies of the project. It's not clear if those studies will still take place, as the government has approved the ESIA and allowed HKND (the company building the canal) to start construction:
Canal commission representative Manuel Coronel Kautz said the commission's decision authorizes China's HKND Company to start structural and construction design work [...] The canal, scheduled for completion in December 2019, will cut across the middle of the country and bisect Lake Nicaragua, known locally as Lake Colcibolca — the second-largest lake in Latin America and the largest drinking-water reservoir in the region. The canal will also cut through the Cerro Silva Nature Reserve.
One thing that's clear from the ESIA (developed by consulting firm ERM) is that while a net positive impact on the environment and local communities is possible, it remains an unlikely outcome under current planning scenarios:
The report says “the government would be wise to consider engaging with international development agencies such as the World Bank or the Inter-American Development Bank,” to avoid damage in sensitive areas like the Mesoamerican Biological Corridor, the Indio Maíz Biological Reserve, the San Juan River, Lake Cocibolca and surrounding nature reserves.
“The study says that in normal situations, these areas would generally be considered untouchable due to their social and ecological fragility,” López noted.
ERM says that if further studies are not conducted and “mitigation and offset measures” are not successfully implemented, “biodiversity impacts would be significantly worse than described.”
It recommended further studies to identify seismic risks posed by construction of the canal; gauge the impact of dredging in the lake; identify the threats from the introduction of saltwater into the lake; and assess the risk of a reduction of the outflow of water from the lake to the San Juan River.
It also concludes that without the implementation by HKND and the government of the environmental and social mitigation measures recommended in the report, not even Route 4 – the one that was selected and the only one considered viable – would have the positive net impact for the environment that could justify construction of the canal.