Environmental water allocations are an increasingly important management option, especially in the Murray-Darling Basin with the implementation of the Basin Plan. Carp are a highly visible, widespread and abundant alien pest fish species that has invasive species attributes (e.g. high fecundities) that allow their populations to expand rapidly. Their spawning and recruitment is enhanced by flooding and hence there is concern that some environmental watering may lead to increases in their populations. To date, most management of environmental flows has ignored the issue of carp production, with most carp management (since the 1970s) focussing on population removal options. This paper illustrates the utility of a carp population model (see accompanying Todd et al. paper) to attempt to ‘quantify’ changes to carp populations from range of environmental watering scenarios including: differences in water allocations; habitats (especially the main channel and off stream wetlands); and sequencing of flows . Changes to carp populations are placed in the context of other events such as natural flooding and habitat changes. Risk assessments are conducted and management recommendations made to mitigate any impacts of carp. These include: that E-flow objectives for native biota must remain paramount; carp populations increase due to a range of reasons; carp must be managed in conjunction with flows and each carp ‘hotspot’ and each major watering site should have a carp management plan; populations need to be monitored; and use of regulating structures should be seen as major experiments relating to carp.