The town’s centerpiece fountain and lake will be the focus of a special meeting for the Town Council on Thursday this week.

The council will hold the special session beginning at 5 p.m., just prior to its regular 6:30 meeting tomorrow, Sept. 1.

The special meeting will focus on four aspects of upgrading the systems that maintain water quality in the lake and the technical and mechanical systems that operate the pumps and water quality equipment.

One aspect is a proposal by the Fountain Hills Sanitary District to provide water for irrigation directly from its advanced wastewater treatment facility on Kiwanis Drive.

Implementing that plan will require a new storage facility to hold any irrigation water.

Coates Irrigation of Gilbert has provided a report on four options to be considered for water storage. They range from a 400,000 gallon tank to an isolation dam within the lake to separate the irrigation water from the rest of the lake.

An above ground steel storage tank to hold that amount of water would need to be 70 feet in diameter and 15 feet in height. It could possibly be built within the existing enclosed pump house yard. While this option was studied and is being presented, it is not recommended by the consultant.

Underground storage options include construction of a concrete tank approximately 60-feet square and 15 feet deep. Another would be the installation of a series of fiberglass tanks. It would require eight 50,000-gallon interconnected tanks.

Either of these options would need to be sited under park turf areas or parking lot, to be restored after installation.

All of these tank options would also require separate equipment for pumping electrical power.

The option for an isolation dam could use much of the existing infrastructure related to electrical, pumping and piping.

Construction of the dike would require a draw-down of the lake. The plan would take a dam 25 feet in length and 12 feet high near the entry to the pump house bay.

While the isolation dam has been discussed and is likely the least expensive option for storing irrigation water, it also has a significant drawback in that it has the potential to make the water quality in the rest of the lake worse.

In a separate report to the council, water consultant Dr. Fredrick Amalfi said isolating the irrigation water would eliminate turnover of the water in the lake, causing a potential increase in algae blooms, odors and oxygen depletion.

Amalfi proposes a number of improvements that could mitigate the issues with lack of replenishment of the water. Those include the increased use of algaecides, application of light-inhibiting aquatic dyes as well as stocking of weed-eating fish.

The most important upgrade, according to Amalfi, would be the repair and expansion of the aeration system within the lake.

He calls for repairing the existing 12-diffuser system, adding another 16 improved diffusers and 10 horizontal water circulators.

The proposal calls for the installation in three phases.

The council has also been considering a possibility of upgrading the electrical systems and technology involved in operating the fountain pumps.

An engineer with Quantum Integrated Solutions in Tempe and an engineer with Keller Electric in Phoenix will be at the meeting to discuss this potential upgrade.

They will talk about variable frequency drive and soft start application for the fountain pumping operations. It has been proposed that the upgraded electrical equipment could save the town considerable dollars in operation costs.

The 5 p.m. special meeting will be held in council chambers at Town Hall and is open to the public.