Hi, I have been working on ...

Hi, I have been working on hydrological circle and water transfer through it, and impact on climate, question you raised is quite important as it is proven that more water in atmosphere triggers more intense weather, as part of my research is defining thresholds for drought and your issue is exact cause of local or microclimate change. If you use simple thermodynamics equations you will see that energy transfer in small boxes (microclimate level) are highly influenced by amount of free water available, or available water for evapotranspiration, if you extract in any other way water from the system you are influencing drought and supporting system to develop drought prone environment, as each box has its balance equation according to landscape and amount of water in it, structure of urban bounds and etc. As well what is important for microclimate is type of watershed you have, is it steady water surface as lake or rapid one, or is it a swamp each requires different amount of energy to transfer water from surface to atmosphere. So direct answer on your question is that water harvesting is pushing system to more arid in case you are not returning water to the system if you want proof just use simple balance equation and thermodynamics