Six homes in Manteca either starting construction or that have just been built paid $17,722 in interim levee impact fees toward what ultimately is expected to be a $176 million solution to protect southwest Manteca, all of Lathrop, and the Weston Ranch neighborhood of Stockton from a 200-year flood.

The homes are the first of almost 2,200 that Manteca expects to ultimately allow to be built going forward in the 200-year floodplain established under state directive. The homes — along with future commercial in the floodplain including the 500-room Great Wolf Lodge resort expected to break ground in August — will ultimately pay $26.9 million toward Manteca’s pro-rated share of the overall $176 million levee enhancement project that is still being developed.

The flood protection effort as mandated by Senate Bill 5 passed in 2007 was updated for the City Council last week when they approved a $65,000 loan as seed money for the San Joaquin Flood Control and Water Conservation District to continue advancing efforts to finance the project. All of the agencies involved — the cities of Manteca, Lathrop, and Stockton as well as San Joaquin County — are advancing $65,000 in “loans” to bankroll work on funding sources. The loans may be repaid after funds are secured.

The initial tasks for the effort include developing a regional levee impact fee program, an assessment district overlay, establishing enhanced infrastructure financial district efforts, and coordinate the local-cost share effort needed to advance state and federal funding for the project.

Manteca adopted its interim levee impact fees that cover new construction within the 200-year flood zone in March of 2017. Those fees are:

$3,145 for a single family home.

$1,417 per 1,000 square feet of commercial.

$1,096 per 1,000 square feet of industrial.

$904 per unit of multiple family complexes.

Those fees at build-out are expected to generate $13.9 million. Unless federal or state funding falls into the cities’ laps, the odds are a benefit assessment district (BAD) will be pursued.

Should that happen the formation of a BAD would be a forgone conclusion. A BAD could be created by owners of developable land outvoting owners of existing homes and businesses since California law requires a vote of property owners weighed by the amount of land they own and not by registered voters.

It requires a public hearing that also serves as a protest hearing. If the majority supports its formation at that time the district can be formed.

Without the BAD, the raw land cannot be converted into housing. That would mean new homes would be hit twice: First for fees when the building permit is issued and then again if and when a BAD is put in place.

Critics have noted the state doesn’t require levees to be upgraded unless cities want to allow new construction that didn’t have specific approvals by July 1, 2016.

But the odds of the city not pursuing 200-year flood protection have always been next to none regardless of the desire of residential developers in southwest Manteca.

That’s because a 200-year flood would damage the city’s nearly $100 million wastewater treatment plant facility as well as impact 120 acres they own where Great Wolf is building along with a family entertainment zone the city is pursuing.

It also isn’t clear whether the treatment plant could be expanded for growth elsewhere in the city if 200-year flood protection isn’t secured.

While formation of a BAD would only directly impact a relatively small handful of Manteca homes already in place, part of the cost — although a comparatively small share — would be covered by all homes and businesses in the city. That’s because whatever share of the overall cost is assigned to the large acreage the city owns at the wastewater treatment plant should a BAD be formed would be charged off to city sewer customers.

Manteca expected to collect $175,000 more in interim levee fees by the end of 2018 when another 55 new homes are expected to be started in the impacted area. The area where the fee applies is everything west of the Airport Way corridor on both sides of the 120 Bypass and the land to the east of Airport Way south of the Bypass to a point roughly halfway to Union Road.

What would impacts

of 200-year flood be

Should a 200-year flood occur with multiple levee failures along the Stanislaus and San Joaquin rivers south of the Interstate 5 bridge before the merger with the 120 Bypass, engineers have indicated it would:

flood 4,200 existing homes with 3 feet or more of water.

endanger and force the overall evacuation of 46,500  residents in Lathrop outside of River islands, Weston Ranch in Stockton, southwest Manteca, and rural areas

force the evacuation of San Joaquin Hospital — the county’s major trauma center — as well as the county jail.

force first responders at five fire stations, the Lathrop Police Department and the county sheriff to abandon their stations and key communication centers in the middle of a major emergency.

Lathrop High and Weston Ranch High would have water flowing through their campuses as would six other Manteca Unified elementary schools.

force the closure of portion of Interstate 5 — the major West Coast freeway running from Mexico to Canada — and the 120 Bypass.

water would swamp the wastewater treatment plant serving 75,000 existing Manteca residents and more than 13,000 of Lathrop’s nearly 20,000 residents.

disrupt Union Pacific Railroad train movements as well as damage tracks that Altamont Corridor Express relies on.

182 commercial and industrial properties from Costco to the Lathrop Target and Tesla Motors to Simplot would be flooded.

And that’s just for starters. Modeling shows a number of existing homes would likely suffer water damage in fringe areas that could receive upwards of three feet of flood water.

Manteca, Lathrop, and Stockton aren’t the only communities impacted by the Senate Bill 5 mandate. There are 85 cities in 33 Central Valley counties that have to comply.

To contact Dennis Wyatt, email dwyatt@mantecabulletin.com