Thresholds Database > Drought coping strategies; Valencia, Spain

Certainty of shift: Demonstrated
Location: Europe, Spain, Valencia, Turia River area
System Type: Social-Ecological
Regime Shift Category: 3d
Ecosystem Type
Spatial Scale
Type of Resource Use
Number of Possible Regimes
Ecosystem Service
Mixed subsistence and commercial farming; food and fibre, water regulation
Time Scale of Change
Resource Users
Reversibility of Shift


The region of Valencia is semi-arid with a high variation in rainfall from year to year. A system of canals which deliver water to farms, has been operating in the area for over 600 years. A water management regime was implemented to maintain a fair and equitable system of water provision to farms, irrespective of the type of crops grown. It provided water to those farms most in need during drought conditions. In 1951, the Generalisimo Dam was completed to regulate the extreme fluctuations in the flow of the Turia River.

Alternate Regimes

1. Abundant water - farmers could take as much water as they needed.

2. Seasonal low water - farms received water under a rotation scheme for a fixed amount of time and water was not to be wasted.

3. Extreme drought - farms most in need of water were given priority.

Fast or Dependent Variable(s)
Water allocation pattern
Slow or Independent Variable(s)
Level of water in the river
Disturbance or Threshold Trigger(s)
Water availability triggered the allocation rule
External / Internal Trigger


When river levels passed certain thresholds, the rules that governed the availability of water to farms changed.

Management Decisions in Each Regime

State 1: No rules (unrestricted use).

State 2: Farms received water under a rotation scheme for a fixed amount of time and water was not to be wasted.

State 3: Farms most in need of water were given priority.

States 2 and 3: A tribunal and syndic (chief executive) strictly managed the system. Farmers monitored water use by their neighbours and ditch riders patrolled the canals to ensure farmers were not cheating the system. Fines were imposed if farmers were caught cheating.

Jacqui Meyers


CSIRO Sustainable Ecosystems,
PO Box 284,
Canberra ACT 2601

Physical/Climate, descriptive, Institutional Mechanisms


Ostrom, E. 1990. Governing the Commons: The Evolution of Institutions for collective Action. Cambridge University Press. (D)