During 2021–22 the Peel–Namoi catchment experienced various climate conditions with a developing La Niña event. This resulted in wet conditions and generally cool temperatures. Keepit and Chaffey dams filled in late July and August, respectively. Both storages spilled water throughout the year and maintained 100% storage capacity. General security allocations reached 105.3% in the Lower Namoi, and 100% in the Peel, as well as 100% allocation in the Chaffey Environmental Contingency Allowance.
These changing circumstances heavily influenced the watering approach and outcomes sought. Environmental water managers adapted their watering plans in response to catchment conditions and changing environmental needs.
About the catchment
The Namoi catchment is in northern NSW and covers an area of 42,000 square kilometres. Located in a temperate climate zone, rainfall typically occurs in summer. The major regulated rivers are the Namoi and Peel, with major water storages at Keepit, Split Rock and Chaffey dams. The Namoi River flows into the Barwon at Walgett.
The lower Namoi catchment is a highly modified landscape, though remnant wetlands are present along the floodplain anabranches downstream of Narrabri, known locally as warrambools. These provide important habitat for waterbirds and nursery areas for native fish.
The Namoi and Peel rivers support native fish including Murray cod, silver perch and freshwater catfish. The Namoi River between Gunnedah and Narrabri provides important habitat for critically endangered silver perch. Lake Goran, in the unregulated Mooki catchment, is listed as a wetland of national significance, and provides habitat for waterbirds when inundated.
The Namoi River is the second largest contributor of flow into the Barwon River, providing an important source of water and opportunities for the movement and survival of native fish.
The Namoi is Country to the Gomeroi/Kamilaroi First Nation.