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Lake Thunderbird Watershed

What is a watershed?

A watershed is an area of land that catches and drains water into a creek, stream, or lake. Everyone lives, works, and plays in a watershed.  That means that everything you do has the potential to affect our water quality.   

Facts about Lake Thunderbird and its Watershed:

  • Construction began on the lake in 1962 and was completed in the 1965.
  • It was built by the Bureau of Reclamation to provide drinking water to Del City, Midwest City, and Norman.
  • Norman citizens are the only ones who both contribute stormwater to and consume water from Lake Thunderbird.  In other words, we drink our stormwater.
  • It was designated as a Sensitive Water Supply lake by the State of Oklahoma in 2002.
  • It was listed on the Oklahoma Department of Environmental Quality (ODEQ) 2008 303(d) list, which lists the waterbodies in the state that don’t meet water quality standards.
  • Sediment and nutrients, like nitrogen and phosphorus, are the pollutants causing the impairment.
  • In 2013, ODEQ established a Total Maximum Daily Load (TMDL) for the lake in an effort to improve water quality.
  • The City of Norman has developed Compliance and Monitoring Plans , which spell out how the City will meet the requirements of the TMDL.  These plans were adopted by City Council on October 25, 2016, via Resolution No. R-1617-41 .


What is a Total Maximum Daily Load or TMDL?

A TMDL is a calculation of the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards.  A TMDL is developed after a waterbody is found to be impaired through water sampling and analysis.  It sets limits on various sources of pollution such as industrial facilities, municipal wastewater treatment plants, or municipal storm sewer systems in an effort to clean up the water and make sure water quality standards are met.  


A TMDL has been developed for the Lake Thunderbird watershed.  The pollutants of concern in this watershed are nitrogen, phosphorus, and sediment.  Nitrogen and phosphorus comes from fertilizers and pet waste.  Sediment comes from construction sites, agricultural practices, and streambank erosion.  We will all have to work together to reduce the amount of these pollutants being discharged to Lake Thunderbird by reducing the amount of fertilizer we use, picking up after our pets, and ensuring that our septic systems are properly maintained.

How is the City dealing with the Lake Thunderbird TMDL?

The Oklahoma Department of Environmental Quality required the City to develop compliance and monitoring plans to describe how we will meet our requirements to reduce the amount of nitrogen, phosphorus, and sediment in our stormwater runoff.  These plans were adopted by City Council on October 27, 2016, and include a 5-year schedule of monitoring and other activities to meet these requirements.
City of Norman Lake Thunderbird Compliance and Monitoring Plans

Where can I find the monitoring data?

Monthly monitoring data will be posted here.

2016: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sept | Oct | Nov | Dec