The effect of climate change on groundwater recharge is becoming increasingly important and requires a resilient management model for a safe water supply. A larger view of the system must be adopted, and humans must become only a part of the whole. This work presents a methodology to evaluate the sustainability of water resources in a watershed using a simplified water balance method. The methodology uses available data from weather stations and the historical analysis of temperatures and precipitations over 95 years. The results obtained in a previous project were considered to extend the plain weather station data over the entire watershed. Results present a good agreement and allow us to conduct a preliminary analysis of the water system’s reliability. The Mt. Lepini aquifer appears in a critical situation where the discharge is directly connected to the recharge with a failure rate of 83%, considering the average mean discharge of 427 Mm3/y. The management of this water system should be conducted considering all the ecosystem services, not only the water supply to human activities but also the existing water ecosystems present downstream to the spring systems.

The Pantanello Natural Park (Pontine territory, Central Italy) is the result of a rewetting project that created five para-natural basins and new habitats at the foot of the Lepini Mountains (Monumento Naturale Giardino di Ninfa). In the present paper, we describe the hydrological model implemented by using data and information from the plan project, high-resolution topographic data (Lidar), and monthly meteorological and climatic data from 2010 to 2020. The model is designed to identify the conditions necessary for effective water-resource management, a key factor for ensuring the long-term success of rewetting interventions and the ecosystem services they support. The recent water crisis, primarily caused by increased use of the spring that feeds both the wetland system and the local population, has significantly affected the ecosystem. The use of the model highlights that, in 53% of cases, the system condition is dry when no external supply is considered. We found a huge improvement: considering a supply of 10 L/s from April to September, the proportion of dry cases reduces to 10%, highlighting the substantial benefits of targeted water supply management.