McKinley Avenue could one day define the outer reaches of southwest Manteca and how that part of the community develops.

The north-south road may eventually swing eastward and align with the envisioned new Austin Road/Highway 99 interchange. Depending upon its exact alignment it may end up being a four-lane boulevard or a two-lane collector street.

Whatever the future holds for McKinley Avenue may also rely in part on the input the City of Manteca receives during a workshop Wednesday at 6 p.m. in the McFall Room of the Manteca Library on Center Street.

The discussion will center around alignment refinements as well as flood protection based on input received during the initial workshop on the McKinney Avenue Specific Street Plan.

Manteca’s ultimate southwest boundaries – as well as the preferred alignment of McKinley Avenue - may be determined by Mother Nature. Nine different floods since 1929 – with the latest occurring in 1997 – have repeatedly shown water can come almost as far north as Nile Garden School when levees fail on the Stanislaus and San Joaquin rivers.

Community Development Director Mark Nelson noted that changing federal flood zone rules may give the city little option in how far south to go. It would dovetail into a long-held consensus that the flood zone ultimately will dictate how far Manteca grows to the southwest.

Changes in the Austin Road Business Park plan also will impact the ultimate McKinley Avenue alignment and width.

The Austin Road interchange – that will be located farther south on Highway 99 than the existing crossing – is the key for the proposed Austin Road Business Park.

The 1,050-acre project is moving through the environmental review process and pre-annexation process. It could generate as much as 13,000 jobs primarily in distribution centers.

Nelson noted that a growing number of firms look at the Manteca-Lathrop area as being ideal in terms of logistics to serve markets in the Bay Area, Sacramento, and down the valley.

The proposed $110 million Austin Road interchange is key to complete build out of the business park. The interchange is expensive as it must also span the train tracks just like the Jack Tone Road interchange does plus a segment of Highway 99 must be shifted to accommodate it.

It is possible, however, for the project to start development and generate jobs to a certain point and still be served by the existing Austin Road interchange dating back to the 1950s.

The 1,050 acres abuts Woodward Avenue and Highway 99 to the north, an imaginary line if Highway 99 ran due south at the interchange with the 120 Bypass instead of angling off to the southeast, and future Ripon city limits on the south as well as the east.

It would have 3.5 million square feet of general commercial or about four times the amount of square footage as The Promenade Shops at Orchard Valley. It would also have 8 million square feet of industrial, business park, and office use plus 3,400 homes. This is also where the proposed Manteca Convention & Visitors Bureau events center and 5,000-seat amphitheater is proposed.

The industrial uses would generate between 3,000 and 6,000 jobs while the retail portion could yield up to 7,000 jobs.

The homes could accommodate up to 10,200 residents are just under a sixth of the city’s current population.

A much smaller business park – often dubbed Tara Business Park – has been envisioned just south of the McKinley Avenue interchange. Due to a decision not to mix truck with neighborhood traffic it is not expected to include distribution centers.

Nelson said the odds are it will be a somewhat smaller footprint with offices and commercial.

The Austin Road interchange is farther along in the planning process than the McKinley Avenue proposal. As things stand now, the odds are stronger that the Austin Road interchange will be built.

What happens at McKinley Avenue depends upon the market and how development plans unfold.

Deputy City Engineer Frederic Clark noted that there is no timetable for developing any segment of McKinley Avenue. Instead, the lull in development is being used to explore what options would be best for overall development.