"We want to make sure everyone in the community is satisfied with the plan," said Frank Smith, chairman of the seven-member advisory committee.
The committee, made up of Washington Township residents, began working on a management plan about two years ago, Smith said.
The 21-page document outlines background information about the land, goals and objectives - including specifics on management and control - and policies and procedures.
The committee had to "cover the whole scope" of the wetland, Smith said, including looking ahead to consider factors that could affect the area later on.
In 1990, Charles S. and Amelia Gardner and Letitia G. Gardner donated the preserve in memory of Charles S. and Elizabeth C. Gardner and Dr. and Mrs. Harvey C. Bridgers.
Though little is known about the natural history of Happel's Meadow, geologists believe that it may have been a lake bed at one time, possibly having volcanic origin, according to the management plan.
At one time the property was known as Bear Swamp and may have been a peat bog.
Today, more than 70 species of birds and 200 species of plants - eight of them rare - inhabit Happel's Meadow, the plan states.
During heavy rain, the wetland collects much of the surface water and slowly releases it, reducing the risk of flooding to neighboring and downstream land.
The wetland also filters out impurities in the water, restoring healthy ground water systems, according to the plan.
The public is invited to tonight's meeting, set for 7:30 p.m. in the township building.