It’s clearer than ever that the No. 1 cash crop on the disappearing sandy plains of Manteca and Lathrop is housing.

As of Jan. 3 the City of Manteca had 10,550 housing units in the proverbial “pipeline”. Meanwhile in Lathrop just one housing development endeavor — River Islands — has another 13,000 plus homes it can still build.

Based on current yields of 3.11 people with each additional housing unit built, those additional homes have the potential to add more than 71,000 people to Manteca and Lathrop. That’s a population higher than the 2010 census count for Manteca that was 67,096.

The Manteca tally includes finalized subdivisions and apartments with approved maps and site plans that are either ready for permitting or are going through the final plot plan approval. It also includes entitled subdivisions with approved tentative maps meaning if they meet conditions they will be granted final maps needed to start building.

Then there are subdivisions and apartments in the application process. The overall 10,550 number doesn't include a just proposed project along Airport Way consisting of up to 123 housing units that are expected to be primarily duplexes.

River Islands is a different animal with its remaining lots. That’s because unlike the Manteca projects that involve a multitude of developers and builders to produce finished lots for building there is just one developer involved in the process as it has been from the start of the process more than 20 years ago.

As such the remaining 13,000 housing units of the 15,001 approved for the planned community being created on the most southern Delta reclaimed island have an extremely high likelihood of being built.

That doesn’t mean the 10,550 housing units in various stages of approval in Manteca are wildly speculative, quite the contrary. Back on Jan. 5, 2012 the City of Manteca released a list of various projects in the development pipeline that represented 10,828 housing units. In other words there were 312 more housing units in the queue 10 years ago than there are today in Manteca.

The 2012 list was whittled down by roughly 6,000 based on homes and apartment units that were actually built. That is how Manteca’s population has soared by more than 20,000 — more than the current population of Ripon — in 10 years going from 67,735 residents to nearly 87,000 today.

That list in 2012 included Austin Road Business Park that had residential provisions that includes 5,026 housing units.

While some of the envisioned housing in the overall plan for the Austin Road project were built, most of those housing units are not counted in the current count because much of the envisioned endeavor has fallen by the wayside  and been replaced by proposed projects elsewhere.

That, however, doesn’t mean they will never be built.

Based on the general plan update that has been underway for four years, the zoning attached to land within the existing city limits has a designed holding capacity of 36,650 more housing units including 26,654 single-family homes.

Those numbers include projects now in the housing queue. If you take the effective yield rate of housing units in Manteca today each home built will add 3.11 residents. That means projects in the housing pipeline plus what could be allowed are likely to generate 110,000 more residents at buildout giving Manteca a population of 198,000.

That number can clearly go higher under the planning Manteca is now targeting in the general plan update. That’s because in the proposed sphere of influence — land identified as likely to be annexed to the city at some future date — there are large swaths of land southeast of the city  between French Camp Road and Graves Road and approaching Jack Tone Road in the East that’s designated for residential reserves.

If and when that land is converted into housing units it would create a population base in Manteca that is somewhere between the 2020 census count of 218,464 for Modesto and 314,227 for Modesto.

Toss in River Islands and development potential elsewhere in Lathrop and the cities of Manteca and Lathrop are laying the foundation and building toward to eventually be the combined size of Stockton today. To put that in perspective Stockton is currently the 13th largest city in California while Modesto is the 19th.

None of the projections includes the fact in subsequent general plan updates taking place every 10 years that serve as blueprints for urban growth in California cities can expand spheres of influence of areas that are targeted for future annexations.

While Lathrop ultimately will be locked in by the river and running up against the city limits of Manteca and Stockton the City of Manteca isn’t boxed in. While the area to the south is considered too expensive to take out of the 200-year floodplain meaning that and Ripon will ultimately impede Manteca’s southern advance as the San Joaquin River and Lathrop do to the west, that’s not the case for the east or the north east of Highway 99 beyond French Camp Road.

Based on the general plan, housing growth isn’t all that Manteca is focusing on although it is the most likely to occur based on the market and the city’s location in relation to the job-rich, housing challenged Bay Area and the growing Sacramento region.

The study by BAE Urban Economics notes the preferred general plan land use at full buildout coupled with projects already in the approval pipeline could:

*Add 19.2 million more square feet of distribution centers. That’s roughly 35 additional buildings the size of the 550,000-square-foot Ford Small Parts West Coast distribution center on Spreckels Avenue.

*Create the potential for 11.1 million more square feet of commercial space. That’s about the same area as 80 buildings the size of the 140,000-square-foot Manteca Costco.

*Make it possible for 5 million square feet of additional office space. Based on a 125,000 square-foot floor plan, that’s the same space as 20 Manteca Target stores.

To contact Dennis Wyatt, email dwyatt@mantecabulletin.com