§ 8.1. Drought stage trigger conditions.

The director or his/her designee shall monitor water supply and /or demand conditions, at a minimum, on a weekly basis and shall determine when conditions warrant initiation or termination of each stage of the drought contingency plan. The presence of conditions that warrant implementing a higher level stage of the drought plan is considered to be a "trigger." The director reserves the authority to recommend that a stage not be initiated based on the time of year, weather conditions, total water supply availability, anticipation of replenished water supplies, or anticipation that facilities will soon come on-line to increase water supply/treatment/distribution capacity.

Upon recommendation of the director, the city manager may upgrade or downgrade a stage when the conditions triggering that stage occur. Customer notification of the initiation or termination of drought response stages will be made by the director or his/her designee by:

• Press releases.

• Public service announcements.

• Publication in a newspaper of general circulation to the city within twenty-four (24) hours after the public announcement.

The director or his/her designee shall notify directly, or cause to be notified directly by fax, mail, email or telephone, the following individuals and entities as appropriate to the respective drought stages:

• Mayor and members of the city council.

• City and/or county emergency management coordinators.

• Executive director of the TCEQ (required within five (5) business days of the implementation of any mandatory restrictions.

• Critical water users (e.g. hospitals).

• City of Irving department directors, street superintendents and public facilities managers.

The triggering criteria described below are based on the ability of the city to deliver treated water to its customers. To set trigger conditions, city staff examined models showing diminished water supplies during a drought equal to the drought of record and examined water demand and system delivery capacity. Trigger conditions examine water supply capability and are based on how much water supply or delivery capacity remains available relative to water demand for all or part of the system.

Stage 1 triggers

º Stage 1 is automatically activated every year beginning on May 15 and concluding on September 30 unless the city is already under restrictions from another stage of the plan. It may also be initiated at other times during the year if one (1) or more of the following trigger conditions occur:

• Condition 1: Pursuant to the requirements specified in the wholesale treated water purchase contract, notification is received from DWU requesting initiation of the stage 1 restrictions.

• Condition 2: Water demand exceeds ninety (90) percent of the combined current maximum wholesale flow rate contracted with DWU and from Irving Lake Chapman water supply for seven (7) consecutive days.

• Condition 3: Short-term deficiencies in the city's distribution system limit supply capabilities.

• Condition 4: Supply source becomes contaminated.

• Condition 5: As determined by the director due to drought or reduced water supply.

º Requirements for Termination: Stage 1 of the plan will be automatically rescinded on September 30 of each year, unless one (1) or more of the trigger conditions listed above continue to exist as determined by the director.

Stage 2 triggers

º Stage 2 may be implemented when one (1) or more of the following trigger conditions occur:

• Condition 1: Pursuant to the requirements specified in the wholesale treated water purchase contract, notification is received from DWU requesting initiation of the stage 2 restrictions.

• Condition 2: Water use exceeds one hundred (100) percent of the combined current maximum wholesale flow rate contracted from DWU and Irving Lake Chapman water supply for five (5) consecutive days.

• Condition 3: Short-term deficiencies in the city's distribution system limit supply capabilities, such as system outage due to the failure or damage of major water system components.

• Condition 4: Inability to maintain or replenish adequate volumes of water in storage to provide for public health and safety.

• Condition 5: Supply source becomes contaminated.

• Condition 6: As determined by director due to drought or reduced water supply.

º Requirements for Termination: Stage 2 of the plan may be rescinded when all of the trigger conditions listed have ceased to exist as determined by the director. Upon termination of stage 2, stage 1 becomes operative unless also rescinded.

Stage 3 triggers

º Stage 3 may be implemented when one (1) or more of the following conditions occur:

• Condition 1: Pursuant to requirements specified in the wholesale water purchase contract, notification is received from DWU requesting initiation of stage 3 of the plan.

• Condition 2: Short-term deficiencies in the city's distribution system limit supply capabilities, such as system outage due to the failure or damage of major water system components.

• Condition 3: Inability to maintain or replenish adequate volumes of water in storage to provide for public health and safety.

• Condition 4: Supply source becomes contaminated.

• Condition 5: As determined by the director due to drought or reduced water supply.

º Requirements for Termination: Stage 3 may be rescinded when the trigger conditions listed have ceased to exist as determined by the director. Upon termination of stage 3, the restrictions imposed under stage 2 become operative unless also rescinded.

Stage 4 triggers

º Stage 4 may be implemented when one (1) or more of the following conditions occur:

• Condition 1: Pursuant to requirements specified in the wholesale treated water purchase contract, notification is received from DWU requesting initiation of stage 4 of the plan.

• Condition 2: Same as condition 2 for stage 3.

• Condition 3: Same as condition 3 for stage 3.

• Condition 4: Same as condition 4 for stage 3.

• Condition 5: Same as condition 5 for stage 3.

º Requirements for Termination: Stage 4 may be rescinded when the trigger conditions listed have ceased to exist as determined by the director. Upon termination of stage 4, the restrictions imposed under stage 3 become operative unless also rescinded.

Stage 5 triggers

º Stage 5 may be implemented when the director determines that a water supply emergency exists, based on one (1) or more of the following trigger conditions:

• Condition 1: Major water line break(s), or pump or system failure(s) occur, which cause loss of capability to provide adequate water service.

• Condition 2: Natural or manmade contamination of the water supply source(s).

• Condition 3: As determined by director due to reduced water supply.

º Requirements for Termination: Stage 5 of the plan may be rescinded when all of the trigger conditions listed have ceased to exist as determined by the director.

(Ord. No. 2011-9302, § 1, 12-8-11)