The Montgomery County, MD council has approved zoning restrictions — unanimously — on ‘combination retail stores’, i.e. ‘discount’ stores of more than 120,000 square feet and with with grocery stores and pharmacies inside. This is effectively a special zoning restriction on Wal-Mart, though it affects a few other companies, too.

Montgomery County yesterday joined a growing list of jurisdictions around the country that have imposed tougher zoning restrictions on big-box retailers, marking a victory for unions and Giant Food LLC, which joined forces to lobby for the restrictions.

Now, a municipality trying to regulate Wal-Mart in some way isn’t necessarily a bad thing. Wal-Mart is blamed for causing ‘sprawl’ all the time, but in fact a Wal-Mart store is denser than most U.S. retail operations. A Wal-Mart has about the same floor space as a whole strip mall, but because there’s no space wasted on separating interior walls and multiple sets of restrooms and so forth, you’ve got more net selling space than you do with the same size building split up among multiple tenants.

Because of this greater net density, Wal-Marts cause traffic problems if they’re done wrong. As long as the county is in charge of building and maintaining roads, it makes sense for them to have a hand in determining suitable locations for Wal-Marts.

But that’s not what the recent vote in Montgomery County is about, at all. We didn’t have the county traffic engineer quoted in the story, talking about how they would manage to handle the customers’ cars. We didn’t have the county’s redevelopment poobah, pimping some blighted acres that might be profitable used as a Wal-Mart site. We had unions and Giant Food. The unions don’t like Wal-Mart because they don’t pay people $17 an hour to stock shelves, and Giant Food doesn’t like Wal-Mart because Giant is incapable of competing with them.

Before the vote, a couple of council members cited Wal-Mart by name. George L. Leventhal (D-At Large) said he decided to support the bill after meeting with a local hardware store owner who begged him to keep Wal-Mart out of Montgomery County.

Ahh, land-use regulation. What fun. Home-improvement stores and ‘club membership’ stores are not covered under the law. The coalition of people who came together to protect Montgomery County from this scourge of inexpensive merchandise and entry-level jobs is impressive:

[County Executive Doug] Duncan lobbied members to vote for his proposal, his spokesman, David Weaver, said. He had help from Giant Food, which sent letters to the council supporting the proposed restrictions. Officials of United Food and Commercial Workers Local 400, meanwhile, organized labor, education and women’s rights advocates to testify with them in front of the council in October.

Got that? Unions and ‘education and women’s rights advocates’ are involved in making zoning decisions.