They also called for the premier to order a review of the two environmental impact assessments for the power plant and sugar factory, which would be able to process 20,000 tonnes of sugarcane per day. The sugar factory construction began in June.
The group wanted all sides to make a strategic environmental assessment to study if the areas are suitable for industrial construction, said the conservation group's leader Samai Khotkiew.
Samai submitted the petition to the Prime Minister Office.
Lam Say Bai is a 200km Mul River-connected canal running through Yasothon, Amnat Charoen and Ubon Ratchathani.