Spring cleaning is an annual ritual for houses, dorms and apartments. But for boat ramps?

Every spring, the Evanston Parks/Forestry and Recreation Department must clear tons of sand off the boat ramp just south of Northwestern’s campus — the only boat ramp in Evanston. The sand is moved over to the adjacent beaches.

“It’s an annual project of dredging out the launch ramp,” said Douglas Gaynor, director of the department.

Boat ramps are used to launch boats off trailers into Lake Michigan. A boat trailer is backed down the ramp until the boat is released. Not all boat ramps require such maintenance, Gaynor said, but Evanston’s does each year.

“It depends on the wave action, on how the waters move the sand,” he said. “In some instances you have sand buildup and in some instances you don’t. It’s pretty much of an annual thing here in Evanston.”

The Chicago Park District has a number of boat ramps but only has to dredge out one of them each year — at Jackson Park Harbor.

“Lake Michigan is kind of funny in that way,” said Julian Green, director of communications for the Chicago Park District. “(For) a harbor on the north side the lake level might increase. But on the south side the level might decrease.”

If the lake level decreases, the harbor needs to be dredged so boats do not scrape the bottom. According to Green, ramps farther north in Chicago tend to have higher lake levels, but Evanston’s ramp does not fit this pattern.

Unlike Evanston, the Chicago Park District does not add or remove sand from any beaches.

The dredging requires a permit from the U.S. Army Corps of Engineers. Evanston has obtained a permit, part of which certifies that the sand is clean enough to be moved over to the beach.

The beaches do not actually need the extra sand, but it is the easiest way to cope with the excess sand that has been dredged, Gaynor said.

Moving sand is not all the Evanston parks department must do each spring to prepare the city’s waterfront for the summer.

“We have to put a ramp extension in, we put in a floating dock, and we do dock repairs to the permanent dock,” Gaynor said.

The city also must plant flowers and turn on water to fountains and bathrooms, in addition to raking and fertilizing the grounds and repainting some areas.

— Paul Thissen