4. WATER USE RESTRICTION BYLAW
Overview
In the summer and fall, high household demand for water – particularly for outdoor uses such as lawn watering – coincides with the Ipswich River’s natural low flow period, leading to extreme flow stress that dries up entire streams and causes fish kills. Communities can use a water use restriction bylaw to reduce residents’ water consumption during this critical season. The bylaw establishes enforceable limits on the use of water during periods of high water demand by controlling activities such as lawn watering, swimming pool filling, and car washing. Typically, water use restriction bylaws are structured so that a town’s Board of Selectmen can declare a state of “water supply conservation” or “water supply emergency” after determining that a water shortage exists, triggering a variety of water use restrictions. While the bylaw grants authority to impose restrictions, the details of the restrictions are often specified separately in drought management plans.
Ideally, the declaration of a state of water supply conservation should be based on pre-determined streamflow thresholds in the Ipswich River, rather than left unspecified or discretionary. This will ensure that water conservation measures are put in place early enough to prevent acute flow stress in the Ipswich River and its tributary streams.
Water use restriction bylaws should stringently limit the timing of outdoor irrigation, by restricting water to once a week or less and/or limiting the hours of watering to early morning or after dark, when evapotranspiration is lower. Many towns employ even/odd day restrictions based on residential address, but this approach has not been demonstrated to reduce water use, and may even increase water use by encouraging water use every other day – a frequency of watering that is excessive and may even make lawns more vulnerable during droughts.
Local Examples
Several communities in the Ipswich River watershed have passed water use restriction bylaws or related outdoor water conservation bylaws. Danvers’ bylaw, in combination with its drought management plan, limits outdoor water use seasonally, and uses a series of flow triggers and reservoir and precipitation indices. Danvers (and Middleton, which receives water from Danvers’ system) limits outdoor water use from May through September, and imposes increasingly stringent restrictions up to a ban on outdoor water use, based on Ipswich River flows and reservoir levels. These restrictions include a limitation to hand-held hoses only during periods of low-flow and a total ban on outdoor watering during more extreme low-flow periods. Middleton also has a standard water use restriction bylaw under which the Board of Selectmen may declare a state of water supply conservation that limits or bans outdoor watering, swimming pool filling, and car washing. Uniquely, Middleton’s water use restriction bylaw and outdoor lawn irrigation bylaws apply to private well users as well as those using municipal water supply.
North Andover passed a standard water use restriction bylaw, but adds an automatic lawn irrigation system bylaw restricting the use of automatic lawn irrigation systems. Wilmington also has a water use restriction bylaw that gives the Board of Water and Sewer Commissioners the authority to limit the hours of outdoor watering, impose odd/even day restrictions, or prohibit outdoor watering altogether.
Resources
Massachusetts Department of Environmental Protection, Model Water Use Restriction By-Law/Ordinance (pdf)
Middleton Water Use Restriction Bylaws (pdf)
North Andover Water Use Restriction Bylaw (html)
Wilmington Water Use Restriction Bylaw (html)
(Scroll to Section 43: Municipal Water Supply Use Restriction)
Water Wise Communities: Index
- Introduction & Using the Handbook
- How Development Affects Water (link to IRWA site)
- Checklist: Is Your Community Water Wise?
- Water Wise Tools:
