As the construction of Water Treatment Plant No. 4 begins, the City of Austin will present its recommendations Tuesday night for routing the water transmission mains to Forest Ridge and Jollyville.

The mains will carry treated water from the plant to the City of Austin distribution system.

In Oct. 2009, Austin City Council voted to begin construction on the $500-million plant. Voters approved building the plant back in 1984.

Council had also voted to pay a private water company $3 million to start digging tunnels down to Lake Travis, in phase 1 of construction on the controversial treatment plant.

Many, including three out of seven council members, argued the city should focus on water conservation, rather than spending half a billion dollars on a new plant.

In 2004, the state set a goal for maximum water usage, urging utility companies to keep usage to 140 gallons per person, per day. Austin residents currently use 170 gallons per day, on average.

Proponents argued the city needs to work now to meet a projected growing demand for water in the future.

Money for the plant will come from Austin water customers. Rates are estimated to increase by 12 percent, or about $3 to $4 a month for the average water customer. The increased rate would last for about 30 years.

The plant is scheduled to be operational by 2014. The plant is being built on city-owned land at the corner of FM 620 and RR 2222.

Tuesday's meeting will take place at Concordia University, in the building A auditorium, at 6:30 p.m.