Securing future water supply on regional and local level in the River Lavant Valley, Carinthia

The River Lavant valley in eastern Carinthia (Austria) is one of the province's driest regions, with under 800 mm of average annual precipitation, geology unfavourable to groundwater storage, and few usable springs. Annual precipitation there has fallen by roughly 15-25% over the past century, and the valley has suffered recurring water-supply bottlenecks during hot, dry summers (notably 1993, 2002, 2003 and 2012), a risk expected to increase with continued climate change.

The region's adaptation measures aim to secure continuity of public water supply over the long term on both the supply side (regional network integration, new water sources, expanded infrastructure) and the demand side (early warning and awareness-raising to encourage water-saving behaviour), alongside forest-management measures to protect the water-retention function of regional forests.

Since 1994, the four municipalities of Wolfsberg, St. Andrä, St. Paul and St. Georgen have progressively interconnected their water-supply networks through the 'regional water association network Lavant valley', drawing on 12 springs on privately owned land under long-term contracts and using a central remote-control system to extract only the water needed. In parallel, the town of Wolfsberg has developed new water sources including deep groundwater wells (used only in extraordinary bottlenecks), expanded its municipal network, and set up a crisis management plan and an early-warning system that publishes daily supply status and triggers graduated water-saving restrictions (e.g. bans on filling pools or watering gardens) as stress increases. Regional forest management complements this by promoting drought-tolerant, mixed tree species over vulnerable Norway spruce to protect forests' water-retention and flood-buffering functions.

The regional network has so far safeguarded water supply for approximately 42,000 consumers, and Wolfsberg's local measures have secured supply for more than 7,000 households over the long term. The regional network's transport system can deliver an annual discharge flow of 260,000 m³. Wolfsberg's municipal supply infrastructure now spans 400 km of supply lines, 83 springs, 29 high-level water tanks and 7 UV water-treatment plants.

Success factors included a state-wide water-supply strategy pursued by the Carinthian provincial government since 1984 (backed by a 200-station province-wide hydrographic monitoring network), the personal drive of a single water expert who championed the regional network's founding, and sustained public awareness-raising on water-saving. The network initially faced local opposition on economic grounds, which eased as repeated water shortages demonstrated its value. Even so, extreme dry summers (e.g. 2003) showed the network's capacity has limits, prompting consideration of an interregional extension. The measures only benefit households connected to the public network; scattered rural households relying on private wells remain vulnerable, as connecting them is not considered economically feasible.