MacArthur Lake to Be Emptied : Parks: Draining the water will permit construction of a subway. The city plans major improvements with funds provided by county transit officials.

On Monday afternoon, mallards and cormorants glided across the eight-acre lake in MacArthur Park as a flock of sea gulls soared above, circling for a chance to dive at fish. People strolled along the walkway around the lake and a man stooped to run his fingers through its murky green water.

It was one of the last times, for a long time to come, that such scenes would play themselves out in the park west of downtown. Once a dangerous haven for crack addicts and street people, the park is cleaned up and slated to undergo a major rehabilitation that, one official says, will leave it “the crown jewel of city parks.”

First, though, the lake must become a mudhole.

Monday morning, workers began erecting a high chain-link fence around the lake in preparation for only the second full draining of its water since MacArthur Park was founded 104 years ago. The operation will take up to a month.

The lake has to be drained so workers can begin building a system of tracks underneath it as part of the second phase of the Metro Rail Red Line. It will remain dry for up to three years, but both it and the park will be much better off as a result, city parks and transit officials maintain.

An agreement between the city’s Recreation and Parks Department and the Los Angeles County Transportation Commission, which is building Metro Rail, calls for recreation and parks to receive $7.5 million in compensation for accommodating the underground work, parks department spokesman Barry Simon said.

All but $1.3 million of that sum, he said, is to be used to improve the park--especially the lake, including lining its muddy bottom with tar to help the water stay cleaner, and installing a new aeration system, pump house and fountain.

Other park improvements are to include vandal-proof lighting and new benches and planters.

In addition, the transportation commission has agreed to kick in another $1 million for returning a two-acre portion of the park that is to be the excavation site, and other park areas, back to their original state, Simon said.

“Absolutely not,” he said.

Preparation for draining the lake began last month. One of the first steps was to relocate a flock of domesticated geese and ducks that live at the lake and on an island at its eastern end.

Wild birds, said Simon, will simply stop coming as the water level drops. There are not enough fish to relocate, he said.

Officials do not know how long it will take to clean up whatever is found on the lake bottom, which is 15 feet below the surface in some places.

The water from the lake--23 million gallons--is unsuitable for reuse, even to irrigate crops or landscapes, officials said.