During the early 1900’s a large portion of the Big Swamp was drained under a public works program to ‘reclaim’ the land for agriculture, but by 1912 the Pipeclay Canal project was declared a failure. An article published in the Sydney Morning Herald reported on its failings and the associated environmental effects, which we now know as acid sulfate soils.
In 1999 the State Government identified twenty-six acid sulfate soil hot spots in NSW, four of which are in the Greater Taree local government area. Leading experts in the field recognise the Cattai Creek-Pipeclay Canal area as one of the worst hot spots in NSW.
The impacts of these soils are often experienced on-site with poor agricultural production (limited crop production, water unsuitable for stock). Downstream water quality is the biggest issue which can result in a reduction in oyster production and fish kills. Acidity in this area has had pH readings as low as 2.4 (in comparison, saltwater has a pH of 8). Given the acid is generated when these soils are exposed to air, re-wetting the soils is often the answer.