It is time for Bay State lawmakers to get moving and pass legislation that has been before them for two years - The Water Conservation and Efficiency Act.

This bill would help cities and towns with financial and technical assistance necessary to better protect and manage local water supplies, require the state to protect rivers and streams by limiting water withdrawals to levels safe for fish and wildlife, and require a review of all state laws designed to protect water.

This New Year began with a state task force declaring a "Drought Advisory" for Massachusetts. Since Labor Day, rainfall has been half of what is normal with precipitation so low that stream flow across the Commonwealth dropped to record lows and groundwater levels declined.

Although the Greater Boston water supply at the Quabbin and Wachusett reservoirs remains adequate, many smaller municipal and regional water supplies are perilously low. If precipitation is not above normal over the next few months, many communities could face severe water shortages over the summer.

Most vulnerable are those municipalities that have undergone significant residential development in recent years. The trend has been toward large lawns and extensive use of irrigation systems to keep lawns big, green and growing throughout the summer, no matter how hot and dry the weather. As a result, water use often triples during the summer. This taxes the capacity of public water supply systems, many of which were built when populations were smaller and lawn irrigation demands were minor.

Heavy summer water use for more, greater and greener lawns draws down reservoir and groundwater levels and reduces flows in rivers and streams. When autumn rains fail, as they did last year, water supplies do not recover in time for the following summer. Water levels drop first in streams, ponds and reservoirs, and last in groundwater aquifers. The result can be water shortages that are inconvenient at best, and at worst may threaten public health and safety and economic activity.

In addition to the human consequences of water shortages, environmental consequences can also be severe. Rivers, streams, and wetlands dry up, destroying fish and wildlife habitat. Even in years with normal precipitation, surface waters are severely stressed when large volumes of water are taken to meet demands for lawns. Eventually, these water withdrawals can destroy the quality of the habitat in rivers, streams, and wetlands. Recently, the state's Water Resources Commission found that the Ipswich, Charles, Assabet, Taunton, Parker, Concord, Nashua, Neponset, and Shawsheen rivers are already stressed from inadequate amounts of water.

The serious human and environmental consequences of excessive summer water use can be easily addressed. All we need to do is to get serious about using water more efficiently. This does not mean that we have to give up our lawns. We do, however, need to make them smaller and, wherever possible, replace them with native plants adapted to summers in New England. Where we do use water for irrigation, we need to use it efficiently, only watering when it is actually needed, rather than on an arbitrary schedule.

Using water efficiently has the added benefit of saving money. When communities meet increased water demands by increasing efficiency, they avoid the need to spend large amounts of taxpayers' money finding new sources of water and building larger treatment plants and distribution systems. When homeowners reduce lawn size, replace lawns with native plants, or simply increase the efficiency with which they irrigate, they save money on their water bills.

The time for water conservation and a more efficient use of limited supplies is now. State environmental officials have already taken beginning steps to address this issue by identifying rivers and streams stressed by inadequate amounts of water, developing a state drought management plan, and drafting a policy on landscape water use.

Action, however, is needed at all levels. The legislature must act, cities and towns need to implement measures to encourage and require more efficient water us, and individuals need to reduce everyday water-use and support implementation of water efficiency measures within their communities.

Using water efficiently is good for people and the environment. No significant sacrifice is required, and money spent on implementing water efficiency measures will return dividends in reduced infrastructure costs and improved environmental quality.

Jack Clarke is director of advocacy for the Massachusetts Audubon Society.