For one small stretch of real estate, there are a lot of different development issues along Portland’s central waterfront, so it’s good the city has more than one tool at its disposal. We are seeing two of them playing out at the same time.

An ongoing effort to loosen zoning along the water side of Commercial Street has been sent to the Planning Board and is expected to go before the City Council this summer.

At the same time, one central waterfront property owner is applying for  a tax break from the city to help finance a renovation of the Cumberland Self Storage building to be reused as an office building for the law firm Pierce Atwood.

The two developments are not at odds. They are just different approaches available to the city to address different aspects of the same problem: how to maximize development on the waterfront without crowding out water-dependent businesses.

The tax break would help a private developer finance a deal in exchange for improvements to the pier edges and first floor of the building, which would be reserved for marine uses and comply with current zoning. The city would, in effect, use the tax break to get the developer to do what he would not do otherwise, which is invest in marine business.

The zoning changes could give other landowners additional revenue streams that would support waterfront businesses. The cost would not come as loss of tax revenue, but, potentially, as loss of space for commercial or industrial water-dependent business.

Changing the zoning would require a very delicate balance for the city, and the council will eventually have to decide whether Portland can continue to have a working waterfront with the loss of some facilities.

The deep water in Portland’s central waterfront is a valuable asset that the city should not endanger with too-loose zoning. The businesses and the jobs they produce cannot be moved to some other part of the city. Once working waterfront is lost to other uses, like recreational boating or residential development, it never comes back.

Portland should use all of the tools at its disposal to encourage development in the central waterfront while preserving the industrial deep-water access that can’t easily be replaced.