• Mark L. Johnson

TA Alert! Water Study Session



Marana Water Study Session


Marana will be holding a Water Study Session in the Town Council Chambers on Tuesday, August 24 at 6:00 PM. The main topic will be Marana's Designated Assured Water Supply (DAWS).


We urge all TA members to attend in person or view on-line and provide comments (verbal and/or written). We will be requesting Marana to allow public comment at this important meeting.


Marana has not provided any documents/presentations on their website but if they do become available before the Study Session we will get them to you.


Remember from Water Woes VII that Marana has approved 33,402 residential lots which will consume 10,020 acre-feet/year. However, Marana only has 5,214 acre-feet/year of DAWS available! Marana has over allocated its water supply (by 2 times) and will now try to fix that by increasing DAWS. You can bet the development community will pull all stops to see that this happens.


Any changes to DAWS must be based on sound science, engineering, water management & planning and conservative assumptions--no magic.


In anticipation of this Study Session, here are some suggested comments:


  1. DAWS Transparency- Public meetings should be held throughout the community. A Marana Water website page should be set up to provide the public: (1) all communication especially communication to/from the Arizona Department of Water Resources (ADWR) and (2) all studies, reports, calculations, etc.

  2. Groundwater Modeling-updated regional groundwater modeling must be utilized by Marana Water to accurately predict inflows and outflows from the Avra Valley Aquifer.

  3. Drawdown/Safe Yield-the 1,000' drawdown allowance should not be allowed to determine DAWS. Safe Yield should be defined as a groundwater surplus based on the 20-year running aquifer balance of inflows and outflows.

  4. Reliable & Renewable Water Supply-all Marana Water sources must be existing (not projected) reliable and renewable with executed permanent contracts to cover the 100-year DAWS requirement. This includes the Central Arizona Groundwater Replenishment District (CAGRD) water supplies that are supposedly planned to serve Marana Water. These water supply sources would include Colorado River Water via the Central Arizona Project (CAP), recycled wastewater and other permanent, reliable and renewable water sources.

  5. Colorado River Water Reliability Factor-Marana Water must utilize a 75% reliability factor for its Colorado River Water supply, i.e. only 75% of the allotment can be used in calculating DAWS due to the long-term drought, aridification, etc.

  6. Discount Polluted Groundwater-groundwater supply for the Airline/Lambert and Picture Rocks systems should not be used in determining DAWS as the groundwater is polluted with PFA's and may get worse over time as it has in Tucson.

  7. Water Demand Projections-water demand projections should be based on reasonable and sustainable growth and not drive water supply requirements.

  8. 50-Year Water Management Plan-Marana should refrain from submitting a DAWS application until it completes a comprehensive 50-year Water Management Plan that incorporates Items 1-7.


I will also be pushing these comments as a member of the the Marana Utilities Board. I have my first meeting on September 15.