Rijeka's water system at record water consumption: "We are staying stable mainly at foreign expense"

The water supply system serving Slovenian Istria is facing unprecedented demand due to extreme heat and a bustling tourist season, forcing the Rizanski Water Supply Company to rely heavily on imported water. As of August 13, 2026, the region's daily water consumption has reached 37,000 cubic meters, equivalent to filling 15 Olympic-sized swimming pools. The average current usage stands at 430 liters per second, with domestic sources contributing only around 115 to 150 liters per second. This shortfall has pushed the company to depend largely on neighboring networks, according to Martin Pregelj, director of Rizanski Water Supply. He described the situation as one where the company is “stable primarily on external accounts.” The local water supply is sourced mainly from underground aquifers and the Rizana River, which have proven insufficient during this period of intense drought. Pregelj noted that the river has effectively dried up, providing almost nothing from its source. “We carry the name ‘Rizanski Water Supply,’ but in summer we become less and less of a water supplier,” he said. To maintain stability, the company imports water from adjacent systems, including contributions from the Tržaški Water Supply (10 liters per second), Kraski Water Supply (100 liters per second), and the Istrian Water Supply and Drainage Company from Buzet (150 liters per second). Despite these efforts, Pregelj warned that the network is vulnerable. “Our grid is literally ‘dragging’ on the reliability of others,” he explained. If neighboring systems face disruptions, the impact would be immediate. However, he credited neighboring companies for upgrading their infrastructure in recent years, particularly in Croatian Istria, where reservoirs were filled in time to prevent severe shortages. Residents are being urged to conserve water, especially for non-essential uses such as lawn irrigation and car washing. Pregelj described the irony of selling water while simultaneously asking customers to use it sparingly. Meanwhile, the company is actively seeking long-term solutions, focusing on infrastructure upgrades and repairs. Annual investments come from revenue generated through the network’s operations, with the system spanning 1,000 kilometers in Slovenian Istria alone. Pregelj emphasized that the water supply will eventually need to transcend municipal boundaries and become a national backbone, akin to highways or the electrical grid. He highlighted that the current level of water loss is acceptable compared to other utilities in the country, though aging pipes require constant maintenance. Experts are looking toward European cohesion funds to support further upgrades and new connections. When asked about potential new water sources, Pregelj ruled out desalination of seawater, citing concerns over the enclosed ecosystem of the Tržaški Bay. Instead, engineers are evaluating five possible locations for new reservoirs across Istria. One promising site under consideration is the Griža quarry near Rizana, where mining activities are set to conclude soon. The abandoned excavation could be repurposed into a large reservoir, creating a synergy between industry and water management. Officials working on the innovative project are collaborating intensively to explore this option. The situation underscores the urgent need for expanded storage capacity and improved regional coordination to ensure reliable water supply during future dry periods. Engineers continue to analyze potential sites, with the Griža quarry emerging as a serious candidate for a major new reservoir.