Ponds are commonly constructed in urban areas as part of water sensitive urban design measures to mitigate the effects of urbanisation. They act to slow the flow of water which allows sediment and associated pollutants to settle, thus generating a water quality benefit. Over time the capacity of ponds to remove pollutants, particularly nutrients, has been reported to decline and it is thought that they can become sources of nutrients to downstream waters. Data from natural wetland studies would suggest that fluctuating water levels in urban ponds may enhance their nutrient processing capacity, but little is known about how changes in water level regimes might affect urban systems. Eight ponds in the ACT, of varying age and water level regime, were investigated between late 2017 and 2019 to determine their capacity to remove nutrients. Two of the study ponds were experimentally manipulated in autumn 2018 and 2019 to determine if introducing fluctuating water levels would improve the performance of the ponds. Nutrient concentrations in the inflowing stormwater were found to be high and highly variable, both spatially and temporally. At the downstream sampling locations, the concentrations of key nutrients were significantly lower than at upstream locations, irrespective of age, water level regime or catchment size. There was no clear evidence that the introduction of water level fluctuations significantly increased the nutrient processing capacity of the ponds, nor was there evidence of any associated decline in nutrient attenuation.