* Introduction
* Phoenix Water Planning Boundaries
* Current and Future Water Supplies
* Phoenix Water Demand
* Scenario Examples
* Planning Timeline
* Strategic Planning Concepts
* Download the full version of the 2005 Water Resources Plan (7.9 MB)1
* Download the 2005 Water Resources Plan Highlights Brochure (1.0 MB)1
* Water Resources Acquisition Fee Update
* Salinity Research

photo of employees working on plan next to photo of street traffic

Planning Timeline

For each scenario, probabilities for each projection year were considered in the context of current water supply conditions, demand trends and other relevant factors. Using this evaluation, timelines were developed with the assumption that the region is currently in the early stages of a long-term drought. Historic records illustrate dry periods of between 20 and 40 years duration, within which occasional wet years (such as the winter of 2004-2005) occur. Some climatologists assert that the region may be within such a period now.

small graphic of bar chart of planning timeline of hypothetical worsening shortage to 2030
With this assumption, it can be expected that Phoenix will experience normal supply conditions for approximately 10 years (through 2015). This expectation of normal conditions is based on several factors: 1) Modeling results for the Upper Colorado River Basin , and demand patterns within Arizona, do not anticipate shortage to Phoenix over this 10 year period, thus reducing the probability of shortages; 2) SRP reservoirs filled during the winter of 2004-2005, and are likely to support normal deliveries for several years; and 3) any increases in development densities within on-project areas would not be sufficient to substantially impact increased use of SRP supplies (on an acre foot per acre basis) in this time frame.

If dry conditions (i.e. below normal runoff levels) exist in the time period and continue beyond 2015, it is probable that the region could experience moderate shortages after that time. Low reservoir levels and increasing build-up in Colorado River demands would characterize this phase. Extended dry conditions could ultimately lead to severe shortages.

This view of potential shortage conditions - especially over the next 10 to 20 years - is of value in planning and scheduling water infrastructure improvements. For example, the timelines point to a need for the deployment of "future supplies" by 2015. Thus, supply selection, project design, capital budgeting and construction activities must occur within this ten year period.



1requires Adobe Reader to view

Last modified on 11/05/2008 20:12:53