It may be hard to believe given California’s propensity for ongoing drought, but it was only five years ago that thousands of residents in the South County were evacuated because high water in the San Joaquin River breached a levee in South Manteca.

And one of the mechanisms constructed behind Mossdale Landing Community Park to stop that high water from seeping beneath levees and causing spot flooding on the opposing side will be permanently accessible by the agency that constructed it more than a decade ago.

During the approval of the consent calendar last week, the Lathrop City Council approved an item that will grant Reclamation District 17 an easement to a seepage berm that the entity constructed in 2011 to prevent seepage from the river from flooding adjacent land.

While flooding involves water moving over or through a levee, seepage is where water moves underground beneath the levee and forces the water table to rise above ground level on the opposite side. In 2017, entire fields in South Manteca along the San Joaquin River were inundated with water from seepage.

In approving the item last week, the council entered into a joint use agreement with RD-17 – which maintains the levees along the San Joaquin River along Lathrop’s city limits – that will clearly spell out when the city and RD-17 can access, construct, reconstruct, maintain, inspect, operate, replace, and rehabilitate the facilities.

Given the installation of the berm in 2011, it may have played a part in limiting the seepage during the San Joaquin River’s last high water event in 2017, which resulted in the evacuation of thousands of residents after a levee breach was detected and subsequently filled in an emergency repair that lasted through the night.

To contact reporter Jason Campbell email jcampbell@mantecabulletin.com or call 209.249.3544.