Urban irrigation water requirement is a crucial yet uncertain part of urban hydrology. One of the primary reasons is the need for a high-resolution dataset to model the irrigation water requirement. Additionally, current methods rely on oversimplified approaches borrowed from agriculture. This study introduces a high-resolution urban irrigation model to monitor irrigation water rates. The study aimed to assess irrigation water requirement (IWR) and irrigation water use (IWU) of residential lawns, analyzing 127 houses overall and focusing on a random sample of 30 houses for more detailed analysis. The assessment included modeling the irrigation water requirement at 3 m spatial resolution at a daily daytime time scale. Using historical data from the Las Vegas Valley District and the recommended irrigation rates from local water authorities, we estimated the irrigation water use. The key results include per-unit irrigation water requirements ranging between 12.7 and 20.3 cm per month. The IWU ranged between 12.7 and 76 cm per month. The average per unit excess irrigation varied between 7.6 and 50.8 cm per month. The excessive irrigation, on average, was four months, mainly in the Summer and Fall seasons. The under-irrigation varied between 6 and 8 months and was primarily observed in Winter and the start of Spring. Comparing recommended irrigation rates with irrigation water requirement and irrigation water use showed that 30 houses over-irrigated six and a half Olympic swimming pools. The study concluded that the higher resolution irrigation model with a spatial resolution of 1 m and 3 m could help monitor irrigation water use. In addition, the study concluded that the currently recommended irrigation water needs refinement and can be significantly improved by adopting the framework, especially for arid regions. By understanding the variability in irrigation patterns and the potential for water wastage, regions facing similar challenges can adapt the framework to have a better understanding of the status quo of irrigation strategies.