The Southwest Florida Water Management District extended an emergency authorization allowing the Peace River/Manasota Regional Water Supply Authority (Authority) to utilize its existing Aquifer Storage and Recovery (ASR) wellfields for the temporary production of ground water to meet regional demand.
The emergency order, which was slated to expire July 1, has been extended to Aug. 1, 2008. It must also be temporarily suspended any time the Authority is able to meet demand using its other water sources.
The Authority’s ASR wellfields are normally used to store excess treated surface water from its permitted Peace River withdrawals for later use. The Authority’s existing permit only allows for it to pump previously injected water from this aquifer storage.
However, the ongoing drought has depleted the ASR reserve supplies. The emergency order allows the Authority to draw native ground water from the ASR wellfields to mitigate effects of the ongoing drought on the public water supply.
The Authority’s service area includes North Port as well as Charlotte, DeSoto, Sarasota and Manatee counties (Manatee County currently does not receive water from the authority).
The authorization will allow the Authority to temporarily utilize its existing ASR wellfields for the production of ground water, with a maximum groundwater withdrawal rate of 17.0 million gallons per day.
The Peace River is the Authority’s primary water source to meet the drinking water needs of approximately 250,000 residents in a four-county region. During periods of high river flows, the authority typically stores water in its reservoir and two ASR wellfields for later use during the dry season or whenever river withdrawals are not sufficient to meet drinking water demands.
As of June 23, 2008, the total amount of water in storage (reservoir and ASR
wellfields combined) was approximately 304 million gallons, or about four percent of the Authority’s total storage capacity.
The District has taken other emergency actions to assist the Authority during the current drought. In February, the District authorized the Englewood Water District to help the Authority by providing water to Charlotte County Utilities. This allowed the Authority to reduce the amount of water it supplied to Charlotte County, which helped extend regional water supplies. That order has expired.
Additionally, in August 2007, the District authorized the Authority to pump additional water from the Peace River, when sufficient flows were available, to store in its reservoir and two ASR wellfields to help protect the drinking water supply. This emergency authorization remains in effect.
Since its issuance, the August 2007 order has allowed the withdrawal of approximately 1.4 billion gallons of water more than would have been normally authorized by the Authority’s permit. However, the prospect of additional withdrawals in the next four weeks is diminished due to seasonal and drought-related declines in river flow. Flow should increase and then stabilize as summer showers become more plentiful and productive within the river’s drainage basin.
During the past twelve months (June 2007 through May 2008) the southern basin of the Peace River received only 42.62 inches, compared to a typical historical value of 51.92 inches, resulting in a rainfall deficit of 9.3 inches. During the same period, the lack of rain in the northern basin of the Peace River has resulted in a rainfall deficit of 10.05 inches. As a result of below normal rainfall in the Peace River watershed, the Peace River’s stream flow is well below normal.
The U.S. Drought Monitor has designated portions of the Authority’s service area as experiencing “Abnormally Dry” or “Moderate Drought” conditions as of June 24, 2008. The U.S. Drought Monitor has been detecting drought or drought-like conditions in this area for about two years.