A Long Term Intervention Monitoring (LTIM) program has been established to monitor and evaluate the ecological responses to Commonwealth environmental watering in seven river systems across the Murray Darling Basin. One of the selected areas for the program was the lower Lachlan River system. To determine the effect of environmental flows on fish spawning and recruitment, larval fish were sampled fortnightly from mid-October to mid-December in 2014 and 2015, using drift nets and light traps at three sites on the Lachlan River in the Hillston area, NSW. Flow and environmental conditions were markedly different over the two years of monitoring. In August 2014 a flow of 5 GL of tributary inflows were protected within the river channel to provide cues for native fish to migrate and spawn as well as contribute to habitat access, fish condition, spawning and larval survival. In August – December 2015 a large translucent event (72 GL) was combined with releases of 25 GL to improve ecological conditions and a subsequent 9.4 GL which specifically targeted golden perch movement and spawning. A total of 536 and 1141 larval fish were captured in 2014 and 2015, respectively, across the five sampling events. Five native species (Murray cod, Flat-headed gudgeon, Carp gudgeon, Australian smelt, Eel-tailed catfish) and two alien fish species (Eastern gambusia and Carp) were captured. Spawning of equilibrium and opportunistic species were observed in both years, however there was no evidence of spawning of periodic species. Opportunities for initiating spawning in periodic species are being explored and may be related to a combination of the condition and structure of the population, the timing of flow releases, and the prevailing environmental conditions.