University of Wisconsin - Extension

Many of us can remember sitting on a dock on a crystal clear summer night, the water as flat as glass, the inky black surface mirroring the sky, the great white Milky Way, a falling star tracing a path across the heavens.

"Unfortunately, this precious part of our heritage, the outdoors with only the light of the moon and stars, is fading away," says David Liebl, University of Wisconsin-Extension waste reduction specialist. "Dusk to dawn lights obscure our view of constellations, meteor showers, planets and the landscape lit by the moon."

Many children now see the wonders of the night sky only in pictures or at planetariums. The fading away of the night sky is an issue in cities, in the countryside and in developing waterfront communities.

"The rising cost of waterfront property in Wisconsin provides ample evidence of the importance of the shoreland environment to the people that live along it," explains Bob Korth, UW-Stevens Point/Extension lakes management specialist.

During the daytime this environment is heavily used for recreation. Artificial lighting allows us to engage in nighttime activities that would be impossible or unsafe under normal nighttime conditions. Whether it?s boating, fishing or simply sitting on the porch to read, our enjoyment of the night is enhanced by the use of artificial light.

"At the same time, our rivers and lakes at night provide a quiet open dark space that gives us privacy and an opportunity to enjoy the heavens," explains Korth. "Balancing the ability to see at night with the desire to preserve the beauty of the night is the goal of sensible shoreland lighting."

Sensible lighting can minimize the three most serious problems along shorelands: glare, light trespass and sky glow. "The first principle of good lighting is to illuminate only what we wish to see," adds Liebl. "When we see light from a fixture itself rather than what the fixture is meant to illuminate, we are observing glare."

Light trespass is a light fixture on one property that illuminates an adjacent or nearby property. Much of our exterior lighting shines directly upward, causing the sky above our cities to glow and washing out our view of the dark night sky.

Sensible shoreland lighting does its intended job well, with minimum adverse impact on neighbors and the environment. Liebl and Korth offer the following suggestions for sensible shoreland lighting.

• Provide adequate light for the intended task, but don?t over-light. Choose lights that meet your needs without lighting the entire neighborhood.
• Glare is both the most common lighting problem and one of the easiest to detect and fix. Eliminate glare by shielding light fixtures so the direct rays of light cannot reach our eye.
• Use full cut-off lighting fixtures to minimize glare. Full cut-off means that no light is emitted above the horizontal.
• Retrofit existing fixtures with shields to reduce glare. In some cases, small pieces of aluminum sheeting fitted to the fixture will suffice.
• Use fixtures with high-efficiency lamps, while still considering the color and quality of the light they produce.
• Avoid dusk to dawn security lights. A more effective approach to security lighting is motion detectors.
• When illuminating signs for advertising, position the lights above and in front of the sign, keeping the light aimed at the sign surface.

"Eliminating glare and light pollution saves money while reducing our impact upon our neighbors and creatures of the night," adds Korth.

For more information about improving the nighttime environment on your lake, contact the Wisconsin Lakes Partnership at 715-346-2192 or e-mail Bob Korth at bkorth@uwsp.edu. More information and contacts are available at their Web site, http://www.uwsp.edu/cnr/uwexlakes/.

For information about reducing waste from residential, commercial or municipal exterior lighting, contact the Solid and Hazardous Waste Education Center at 608-262-0385.