Banhados do Delta do JacuÃÂ Biological Reserve () is a biological reserve in the JacuÃÂ River delta in Rio Grande do Sul, Brazil.
The JacuàDelta State Park () was established on 14 January 1976. The islands of Pólvora and Pombas were designated as a Biological Reserve, and other areas could be expropriated. The park covered . It is located in the Porto Alegre metropolitan region in the municipalities of Eldorado do Sul, Nova Santa Rita, Canoas, Triunfo, Charqueadas and Porto Alegre.
In February 2004 the state's Department of the Environment presented a proposal to create the JacuÃÂ Delta Environmental Protection Area (APA), which would include the state park with the addition of to give a total area of . The proposal would include creating the Banhados do Delta Biological Reserve, with an area of , to be used only for scientific studies, with full protection of species.
The state park's limits were redefined on 11 November 2005. The outcome was that the APA, which covers including privately owned land, supports the use of natural resources in a sustainable manner according to a management plan. The State Park portion, which covers all of which is publicly owned, aims to preserve the natural landscape and ecosystem for scientific, educational and recreational use.
The area containing the biological reserve is a water complex formed by the rivers CaÃÂ, Sinos, GravataÃÂ and JacuÃÂ, which form Lake GuaÃÂba. There are thirty islands and mainland areas. Where the rivers meet the GravataÃÂ is heavily polluted by urbanization and industry, and the CaÃÂ and Sinos are heavily polluted by environmental waste. The boundaries of the islands are constantly shifting. The vegetation is typical of wetlands in the region. Despite the proximity to the city, endangered species are found in the delta including otter, capybara and broad-snouted caiman.