Oakwood Lakes Water District that serves a gated community and a mobile home park just outside of the southwest Manteca city limits needs to expand and upgrade its wastewater treatment plant.

Manteca needs to find a way to send storm water from a large swath of southwest Manteca to the San Joaquin River.

The two needs have led to a proposed agreement between the water district and the city that will provide critical services to residents served by both entities will at the same time reducing long-term costs.

The City Council on Tuesday will consider a deal that will send sewer effluent from the 436-lot Oakwood Shores neighborhood and the 57 mobile homes to the municipal wastewater treatment plant. At the same time an easement will be granted along the northern edge of the water district along the railroad tracks to allow construction of a pipe to take city storm water to the river.

It will cost the water district $2.1 million to install pipe to connect with the sewer system and its ratepayers $2.8 million upfront. Each Oakwood Shores home would be charged $6,198 and mobile home owners $5,274 to connect to the Manteca wastewater system. That is in addition to a $43.30 per month charge for each residence to cover the cost of treatment and disposal.

Overall it is initially a higher price tag than the water district expanding and upgrading its plant. But in the long run operating costs will be significantly lower for Oakwood ratepayers.

In exchange for allowing 493 housing units to use existing treatment plant capacity, Manteca is paying $15,140 for a storm system pipe easement.

The storm drainage system as envisioned will cost future homeowners in southwest Manteca that will absorb the cost developers will incur to put the storm system lines in place $4.5 million. That compares to $7.5 million for the only other viable alternative available that includes spending $2.6 million to annex the area to the South San Joaquin Irrigation District to access an outlet to the river as well as $4.9 million for the needed improvements. The savings to future Manteca residents in the area that the storm runoff system will serve is $2.9 million.

The City Council meets at 7 p.m. Tuesday at the Civic Center, 1001 W. Center St.

To contact Dennis Wyatt, email dwyatt@mantecabulletin.com