A common expectation of providing environmental water for fish in regulated rivers is that such flows will stimulate spawning and lead to juvenile recruitment. The Lower Balonne River network is regulated by a number of upstream dams including Beardmore Dam. Downstream of this are regulating structures that determine eventual flow paths. We ran a short-term study in the Lower Balonne river system to investigate temporal patterns of fish larval and zooplankton abundance in two distributary channels (Culgoa and Narran Rivers). Sampling occurred monthly from August 2017 to April 2018. Rain events lead to three stock and environmental releases from Beardmore Dam in this time resulting in two small pulses in the Culgoa River in October and December and a larger flow in both rivers between March and April. Larval abundance was extremely low for all potential species for the whole study apart from small numbers of bony bream in November and December and higher numbers for the species in April. The lack of evidence for spawning from the available species pool is discussed in relation to environmental setting and food availability. The adequacy of occasional flow releases to support healthy fish populations in the Lower Balonne will also be discussed.