Presentations made during Tuesday's Norman City Council special session underscored the importance of implementing the Storm Water and Greenway master plans, to prevent further water quality degradation in Lake Thunderbird, the principal source of Norman's drinking water supply.

Lake Thunderbird is a sensitive water supply lake, serving the City of Norman, Midwest City and Del City. Excessive algal growth in the lake from runoff of nutrients has led to water quality degradation that includes periodic undesirable taste and odor of the finished drinking water, as well as potential ecological and recreational impairment. Increased urban growth in the area is expected to exacerbate the current problems, officials said.

Public Works Director Shawn O'Leary said the improvements outlined in the final reports for its Storm Water and Greenway master plans involve a "large undertaking" that will take as long as 20 years to address, followed by ongoing maintenance.

O'Leary said the plan, which had been in the works for four years, was developed by the PBSJ Corporation and "covers all of Norman -- approximately 200 square miles."

Primary goals and objectives contained in the plan include "obtaining public input, providing public education on important stormwater issues, building consensus and support, addressing water quality and drainage challenges in an environmentally sound manner, enhancing recreational opportunities and developing funding solutions."

Total cost of stormwater improvements over a 20-year period is estimated at $84 million dollars, O'Leary said.

The Storm Water Master Plan proposed to require stream planning corridors; flood plain dedications by easement for streams in the Lake Thunderbird watershed; and side stream buffers of 15 feet or more on each side of the corridors.

Frank Garza of Davidson and Troilo Law Firm, provided information to council concerning adoption of the master plans and other issues. The Lake Thunderbird Watershed Analysis Quality Report, issued in June 2008, said the lake has been designated as a sensitive water supply lake by the Department of Environmental Quality. Garza said the lake's chlorophyll concentration is about "three times the acceptable levels."

Garza said the regulations contained in the Storm Water Master Plan, when imposed, "will improve water quality."

Furthermore, "uncontrolled flood water is a public nuisance," Garza said.

One major problem the city faces is that no easements or accesses exist to repair or maintain its stormwater channels. By the acquisition of drainage easements and rights of way, workers would have access for the maintenance of creeks and detention facilities.

"The City has a duty to abate those nuisances," Garza said.

Garza said the Lake Thunderbird Watershed Analysis Quality Report is "alarming."

"It's imperative that something needs to be done before it gets to the point that we can't drink the water," he said.

Council members discussed the condition of the lake and Norman's streams and channels, and the proposed solution which involves the creation of a "stormwater utility" similar to the water bills paid by Norman residents. The payment would be based on the amount of impervious area owned by Norman residents. This includes all area of a site covered by roofing, plus all area of a site covered by constructed surfaces, such as car parks, driveways and paved areas.

The monthly cost for an average single family home with 3,614 square feet of impervious surface would be $6.74, officials said. Owners of small homes would pay about $4.30 a month and owners of large homes about $8.50 a month.

The projects that need to be done will take several years of collecting fees to accomplish, officials said. Finance officials are considering asking voters to approve the use of a combination of general obligation bonds and stormwater utility fees to make the necessary improvements.

Mayor Cindy Rosenthal asked the Stormwater Task Force to discuss and formulate a resolution or "action plan" for future council consideration.

Tom Blakey 366-3540 tblakey@normantranscript.com