in the total volume declared and paid under the general regime was only of the volume granted a water entitlement can expire if the total volume of water granted has not been used in two consecutive years without explanation since the water titleholder can pay a guarantee fee cuota de garantid to avoid the expiration of the water entitlement the aim of this mechanism is to encourage titleholders that do not intend to use the water to give back their titles the rationale is that unused entitlements generate opportunity costs for society water that is allocated but not used could be used in other activities and generate social benefits