For pedestrians in the Yard these days, the sounds of spring have given way to the grind of bulldozers.

Three separate construction projects are underway in the Yard this semester, and will continue through the end of May.

"What you see now is the opening stages of [the projects]," Director of Planning Kathy A. Spiegelman said.

Harvard Real Estate's (HRE) renovation of Yard dorms is now entering its third summer, Facilities Maintenance has started digging up the ground to reroute storm and sewage pipes, and Spiegelman is supervising a plan to restore the tree canopy above the Yard.

The trees around Yard buildings have been perishing at a rapid rate, Spiegelman said, and many have fallen victim to elm disease. Because full grown trees take years to replace they must be replanted immediately she added.

"We tend to take this for granted, but it's important to have a natural tree canopy for most of the year," she said.

Workers are currently cutting down trees but plan to plant between 50 and 70 new trees in time for Commencement. The trees do not grow well in the summer heat, Spiegelman added.

After Commencement, work on the dorm renovations and drainage project will begin in earnest, said Scott Leviton, assistant vice-president for construction and planning at HRE.

This summer's construction will affect six dormitories, with renovations ranging from Holworthy's overhaul to lesser touchups in Penny packer, Hollis, Stoughton, Grays and Canaday.

"We're going to do bathroom and roof repair. That should make everybody cheer," Leviton said.

Construction workers in the Yard are currently installing a transformer whichwill provide Grays with more electrical power.

Work on this project will be suspended whenstudents return to campus in the fall and will becompleted next summer, Leviton said.

The summer's construction also will feature thererouting of Harvard's storm and sewage drains, aneffort that will require digging up and tunnelingunder large chunks of the Yard, Leviton added.

The combined commotion caused by both projectswill mean extra work controlling traffic in theYard. Some pedestrian routes will be shifted toaccommodate construction, Leviton said, andcontractors will be encouraged not to park theirtrucks in crowded areas.

"It's not going to be easy," Leviton said."People are going to have to be patient andremember that we're making needed renovations onthese buildings."CrimsonJohn C. MitchellOBSTACLE COURSE: The cutting down andplanting of trees has left holes and mounds ofdirt in the Yard.