Construction of a $15 million parking garage and retail project in Broad Ripple could be in jeopardy because the property sits nearly 4 feet below a flood plain.

Local developer Keystone Construction Corp. is requesting a variance to build the three-story garage without the necessary flood protection on the site at the three-way intersection of Westfield Boulevard and Broad Ripple and College avenues.

Keystone’s engineer, Indianapolis-based American Structurepoint Inc., said that a nearby levee, which ultimately will be part of a larger system to be built near White River, provides enough protection for the parking garage.

But Indianapolis Department of Metropolitan Development staff is recommending denial of the zoning change and said the ground floor of the garage needs to be built above the flood plain.

Keystone, however, argued that elevating the ground floor would add too much expense to the project.

Calls to Keystone and its attorney were not returned Monday morning.

The Metropolitan Board of Zoning Appeals is scheduled to consider the variance at its meeting on Tuesday.

The city of Indianapolis is helping to finance the 350-space garage with $6.3 million in parking meter revenue.

It is investing in the project to fix a simmering parking problem in Broad Ripple and to clean up a blighted corner with a long-vacant Marathon station. Keystone will own the project, including the garage, and collect all the revenue.

The mayor’s office sought proposals in March 2011 and picked from seven options, including bids by Kite Realty Group, Browning Investments and Buckingham Cos.

Keystone in December received city approval to construct the building without a required 70-foot setback and no loading spaces for deliveries. Instead, the parking garage would front the streets and be separated only by sidewalks, with street-side loading on College Avenue.

A plan to include a bank and a drive-through have drawn opposition from neighbors who have said it will substantially increase traffic in the area.