Regional Drought Monitoring Map and Water Withdrawal Regulation Portal

Emilia-Romagna’s water cycle is under measurable strain: planning documents for the region’s new water protection plan (Piano di Tutela delle Acque, PTA 2030) cite a 12% rainfall decline over 80 years alongside a 1.3°C rise in average temperature. The region also swings between extremes — severe drought in 2022 was followed by catastrophic flooding in May 2023, when roughly 4 billion cubic metres of rain fell on about 16,000 square kilometres of territory in a matter of hours.

Drought threatens multiple systems in the region: crop yields and agricultural output, public health, hydroelectric energy production, the cost of water sanitation and purification, and the security of drinking water supplies.

Anticipating water scarcity requires real time data and innovative approaches to harnessing data for decision making. Emilia Romagna has delivered region wide monitoring tools – a monitoring map and withdrawal portal. The monitoring map spans eight regional macro-areas plus five Po river points and ten regional river basins, while the withdrawal portal covers surface water bodies across the region wherever a minimum vital flow (Deflusso Minimo Vitale, DMV) threshold applies.

Emilia Romagna’s regional environmental and energy agency- Agenzia Regionale per la Prevenzionie, l’ambiente e l’energia dell’ Emilia-Romagna (ARPAE) operates a data driven drought monitoring and early warning service providing daily updates on drought status across the region’s river basins. The service is publicly accessible through a government run drought portal that provides daily drought indices and meteorological data with intra-regional comparisons tracked against climate projections; water balance and allocation modelling, which simulates changes within the system including diversion scenarios for agriculture; seasonal river discharge forecasts for the Apennine basins with threshold indicators that enable water managers to anticipate when to store, distribute, or reduce water use, rather than responding once drought has set in; and forecast alerts structured around alert zones allowing water managers to take autonomous actions- reducing administrative burden of emergency derogations. View link ↗

The regional drought monitoring map collects three indicators that trace drought patterns as conditions progress from atmosphere to soil to river and can distinguish a dry spell that has yet to become a real problem from a developing crisis, where the deficit has fully worked its way through the system. Cumulative precipitation comparisons indicate if it’s raining enough for the place and time of year, making it the earliest signal of meteorological drought. Water balance, which nets precipitation against potential evapotranspiration, captures agronomic and soil-moisture strain before it shows up downstream, adding important demand-side context, since a heatwave can push water stress higher even when rainfall looks close to normal. River discharge reflects the cumulative effect of precipitation and water-balance deficits filtering through an entire catchment. It is the slowest, but most consequential indicator and is the closest proxy for whether there is actually water available for people to use immediately.

In 2026, ARPAE launched a water withdrawal regulation portal and early warning system to better detect and respond to drought, and to more effectively regulate summer water withdrawals region-wide. This portal provides continuous, real-time monitoring data and clear public communication, so that water users can better understand and comply with any water restrictions, using a red/yellow/green "traffic light" map tied to minimum vital flow thresholds. View link ↗

• Red — basins where discharge has fallen below DMV; withdrawal is prohibited.
• Yellow — basins approaching DMV, where large irrigation withdrawals must be modulated downward.
• Green — basins where withdrawal is permitted within existing concession limits.

The portal runs alongside the map seasonally, from June to October, and is reissued under a new legal determination annually. Through collaboration with both regional public authorities and water management bodies, these early warning alerts help break down silos and administrative burdens around water management, allowing for the seamless connection point between emergency coordination, on-going monitoring, and usage communications.

Defined under Emilia-Romagna’s regional water law, the Minimum Vital Flow (Deflusso Minimo Vitale, DMV) framework sets the regulatory threshold for the minimum water flow that must remain in a river or stream to sustain the aquatic ecosystem, and acts as the threshold beyond which withdrawals are restricted or banned. Specific DMV values for Emilia-Romagna’s water bodies act as the legal basis for the restrictions communicated by the withdrawal-regulation portal. Not only does the portal help better communicate guidelines to users, but it also supports ARPAE in identifying and responding to unauthorized withdrawal during red-zone restrictions, which is a sanctionable violation under regional water law.

How the Region Uses the Portal
The portal is not an alert system, but rather an informational tool based on a traffic-light system. At the regional level, Regional Law No. 9/2026 (LR 9/2026) was recently adopted; it contains provisions concerning Arpae, including the Portal system, and defines specific regulations regarding penalties.

ARPAE monitoring map and withdrawal portal grew out of ARPAE’s existing hydro-meteorological network and the region’s long-standing DMV regulatory framework, with the portal formalizing and automating what was previously a more manual permitting/derogation process.

The system originates from the Arpae monitoring network across the regional territory, which consists of a series of fixed or mobile flow meters placed along various water bodies. This system has been implemented digitally within a GIS tool and superimposed on a regional mapping of basins defined at the Basin Plan level.

Based on the flow reading taken by each individual meter, which is compared against the Minimum Vital Flow (MVF) value relative to that specific stretch of the water body, an internal bulletin is issued. Through a traffic-light system, this bulletin identifies a specific color code that informs the user whether extraction is permitted or not. This information is made visible to users via color-coded mapping on the portal. The monitoring devices, both fixed and mobile, are water level gauges (telehydrometers) that are linked to a corresponding flow value using a rating curve calculated from flow measurements taken during the summer

Owner/operator: ARPAE https://www.arpae.it/it

Governance fit: These tools were developed in response to the Piano di Tutela delle Acque (PTA), Emilia-Romagna’s regional water protection plan. The current PTA dates to 2005, but the region is now developing PTA 2030 to respond to updated EU/national water law and to climate pressures (with cited goals including water savings, water reuse, reduced water loss, small-scale reservoirs, and flood-damage reduction). This connects further up to the EU Water Framework Directive (2000/60/EC) river-basin management planning cycle. View link ↗

The drought early warning and water-withdrawal system sits within Emilia-Romagna’s broader system for managing water resources. ARPAE is responsible for the regional water-demarcation and abstraction regime: it issues and manages concessions for the use of public water and operates the seasonal portal that translates river flows into restrictions on surface-water withdrawals. The region’s integrated water service is organised and overseen through ATERSIR, the territorial agency responsible for the service covering water abstraction, conveyance and distribution for civil uses, as well as sewerage and wastewater treatment. ATERSIR contracts and oversees service providers, which include operators such as HERA, IRETI and Romagna Acque across different parts of the region. View link ↗

The ARPAE portal supports the coordination of the sector during drought events by showing river conditions against the minimum ecological flow (DMV). Where exceptional drought conditions make continued abstraction necessary, the system provides a formal route for derogation rather than leaving this as a discretionary decision by individual operators. Under DGR 802/2022, derogations for legitimate potable and irrigation abstractions can be activated following recognition of district or local water scarcity by the Permanent Observatory on Water Uses. ARPAE receives and assesses applications and, where necessary, coordinates a multi-agency service conference before granting the derogation. The result is a system in which drought information, abstraction controls and water-service delivery remain institutionally distinct but connected: the drought monitoring and river-flow information informs decisions on water availability; ARPAE translates this into enforceable conditions on abstraction; and water-service operators must manage the implications for supply within the wider framework overseen by ATERSIR.

Created under Regional Law (Legge Regionale n. 3/1999), which reformed local and regional administrative procedures in Italy, Regional regulation (Regolamento Regionale – RR n. 41/2001) set the rules for getting public water extraction permits and established a 2026 Regional Government Resolution (Delibera della Giunta Regionale – DGR n. 2067/2015) on minimum vital flow and sanctioning authority for violations. The withdrawal portal operates under a specific annual determination (DET-AMB-2026-3457 for 2026) to operationalize these legislative directives.

ARPAE implements both tools directly, using its own automated hydro-meteorological monitoring network and its authority to issue the annual withdrawal determination.

• Sequencing: the withdrawal portal depends on the same real-time hydro-meteorological network that feeds the drought monitoring map — the monitoring infrastructure had to exist first.
• Maintenance needs: the drought monitoring map updates every morning from automated network data. The withdrawal portal updates weekly, with additional out-of-cycle updates when flows shift sharply enough to require it.
• Data caveats: discharge figures on the monitoring map are provisional pending finalized rating curves; ARPAE flags this explicitly for at least one station (Savio at San Carlo, FC) still being recalibrated after the 2023–2024 floods.
• Lifespan/renewal cycle: the drought monitoring map runs continuously on the hydrological year (1 October–30 September). The withdrawal portal is seasonal, active through 31 October each year and reissued under a new determination annually.

Co-benefits:

• Both tools are publicly accessible, giving water managers and citizens the same shared, transparent picture of hydrological status.
• The monitoring map’s historical benchmarking (back to 1961/62 for precipitation and water balance, 2006/07 for discharge) lets users judge how unusual current conditions are, not just their raw values, and can better monitor changes that signal drought earlier, rather than later, to take appropriate action.
• The withdrawal portal converts what could otherwise require case-by-case derogation review into a standing, rules-based, publicly visible map. This allows more effective sanctioning, while also building community awareness, cooperation, and behavior change to reduce the future water misuse that leads to sanctioning.

Trade-offs / tensions:

• Provisional discharge data means decisions made on early readings carry some uncertainty until figures are validated the following year.
• The withdrawal portal is a threshold-triggered, reactive restriction system — it prohibits withdrawal once flow has already dropped below DMV, rather than anticipating that drop in advance.
• Enforcement remains part of the system: unauthorized withdrawal during red-zone restrictions is still subject to administrative sanction, so the tool functions as a compliance mechanism as well as an informational one.

Harnessing existing data on water availability, and historic water availability data to proactively manage water resources before drought crises. This system uses early signals to identify meteorological drought. This action relied on an existing hydro-meteorological monitoring network into two public facing decision layers.

Clear and transparent live data used to inform water users to build understanding of measures taken to ensure water security. Transparency builds trust between agencies and water users.

Pairing a continuously updated, publicly visible monitoring layer with a rules-based, threshold-triggered restriction mechanism gives both water managers and the public a shared, legible basis for understanding when and why withdrawal limits apply.

ARPAE’s ongoing PTA 2030 planning process is expected to fold climate-adaptation objectives, including water savings, reuse, small-scale reservoirs, and flood mitigation, into the next generation of regional water governance.

ARPAE Forecast-Based Decision Support System for Water Management