Postgraduate: Susan Lutton - Aquatic biodiversity and the ecological value of the ring-tank water storages on cotton farms (wasFCRC1C)

Date Issued:2008-06-30


Globally, natural wetlands are under threat from water resource development

reflecting the need to support a growing population. In the Border Rivers Catchment

in Queensland, Australia, a large irrigation industry coupled with a highly variable

flow regime has necessitated the building of large on-farm water storages and often

associated destruction or isolation of their natural counterparts. With the decline in

abundance of natural wetlands, the presence of these storages on the floodplain has

raised the question of their suitability as alternative aquatic habitat. This project

aimed to investigate the diversity of storages and the structure and function of the

aquatic assemblages they support compared with nearby natural wetlands. These

results were then used to recommend best management practice for optimising both

diversity and ecosystem function in storages.

Initially the physical variety of water storages in the Border Rivers Catchment was

described and their morphology and hydrology compared to that of natural wetlands.

Storages and natural wetlands formed two distinct groups based on morphology.

Storages tended to be large, deep structures with a more regular shape, while natural

wetlands were irregular and shallow with large perimeters. Although there was a

degree of variability amongst storage sites, most fell into one group and were

considered to be a ‘typical’ storage in this region.

Storages primarily function as water supplies and their associated management makes

them mostly unsuitable as ‘replacement’ wetlands. However, given the large numbers

of storages across the catchment, if managed effectively, they may provide an

additional source of aquatic habitat and help maintain regional biodiversity. To

maximise the biodiversity of storages it will be essential to reduce the morphological

homogeneity of storages across the landscape and increase habitat diversity within

storages. In the future, improved design of new storages and alterations to existing

storages and their management could help overcome this problem of low diversity of


As a group, storages in the Border Rivers Catchment are still fundamentally different

to natural waterbodies, with storages being a mostly homogeneous group. If we are to

sustain the aquatic biodiversity in the Border Rivers Catchment and other similar

irrigation regions it will be necessary to preserve the spatial and temporal variation in

habitat evident in natural wetlands.

Show Full Details

This item appears in the following categories