Monday, May 2, 2016
John R. Nolon
Distinguished Professor of Law, Pace Law School
Counsel, Land Use Law Center
Water Scarcity and Land Use Planning
When zoning was created, the availability of cheap and plentiful water was an unquestioned assumption. In zoning’s blueprint, there are few designs for water supply planning. This is the case even though land use planning determines water demand; the number and type of buildings allowed under zoning determine the per capita water use in a given community. Water supply planning was traditionally the province of the municipal water district, a separate water and sanitation district, or similar entity. Most of these were organized under state statutes that were originally – and remain today – legally disconnected from the zoning and land use planning enabling acts. Water demand and water supply planning have never been connected legally or institutionally.
This separation is a serious flaw in the legal system, particularly in those states with drought, limited snow melt, and declining surface and ground water supplies. Recent U.S. Drought Monitor reports state that 38 out of 50 states are abnormally dry. Sixteen of them are in a moderate drought, nine are in a severe drought, two are in extreme drought, and California is in an exceptional drought.
According to EPA, relief is not on the horizon: “Scientists project that climate change will make some of these extreme weather events more likely to occur and/or more likely to be severe." Relatedly, according to NASA, “continued increases in human-produced greenhouse gas emissions drive up the risk of severe droughts in these regions."
These predictions highlight the importance of connecting water supply and land use planning. Not only can land use planning reduce emissions, but, as the Land Use Law Center’s recent experience in the Interior West demonstrates, land use planning can also reduce per capita water use by up to 140 gallons per day. With the populations of these states projected to increase – by as much as 100% in Colorado – reducing per capita consumption is the logical point at which to begin a comprehensive plan to balance supply and demand.
Zoning that permits large lots, low-density, and dispersed development increases water use per household. Compact, mixed-use development requires less water per household than single-family housing. The infrastructure requirements of both types of development are quite different.
In Utah, planners have determined that water demand drops from approximately 220 gallons per capita per day at a density of two units per acre, to about 110 gallons per acre at a density of five units per acre. More modestly, increasing residential density by 20% can yield a 10% per capita water savings. A study of household water use in Sacramento, CA showed 20-30% less water use in a new urban development than in the suburbs. Because of these significant effects, the link between land use patterns created by local zoning and water conservation needs to be clearly understood. Very few other water planning strategies can have a greater effect on limiting consumption.
Communities should begin by integrating water-efficient land use patterns and strategies into their comprehensive plans. Once this initial step is completed, this vision can be implemented through changes to the zoning code that permit water-efficient land uses in areas targeted for development, discourage development in areas targeted for conservation, and foster building types and landscapes that minimize the use of water.
Similarly, communities with limited room to grow can modify systems to accommodate higher densities and infill development. New forms of zoning, rather than those found in traditional residential zoning district provisions, can be adopted; ones that use new and varied ratios regarding setbacks, lot coverage, open space, livability space, and parking.
Building and land use regulations can reduce water use in several other ways; for example, by mandating water-efficient interior and exterior fixtures and by requiring exterior landscaping practices and plants that reduce water use.
The Land Use Law Center’s Guidebook for Municipal Planners (cited below) in the Interior West states discusses and illustrates several options for communities to consider in their efforts to foster water-conserving land use patterns, such as:
- Incorporate water-conserving land uses into as-of-right permitted uses;
- Foster water-efficient densities by permitting accessory dwelling units;
- Incorporate water-conserving land uses into conditionally permitted uses;
- Conditionally permit water-intensive uses upon water-conservation measures;
- Condition rezoning on water-conserving practices;
- Incentivize water conservation through bonus density zoning;
- Use planned unit development regulations to foster water conservation;
- Create a water conservation floating zone;
- Use overlay zoning to designate areas appropriate for conservation and those prioritized for growth; and
- Establish a transfer of development rights program with sending districts to preserve green infrastructure and receiving districts to channel economic development.
Which of these options to choose depends on a number of factors, including the current land use configuration and types of buildings in the community. The pattern of development fostered and types of buildings allowed by zoning must respect the current architecture and land development of the community and build gradually from that base. The biggest factors to consider are density, the utilization of present infrastructure, and the cost of needed additional infrastructure.
For more information see the Land Use Law Center’s Integrating Water Efficiency into Land Use Planning in the Interior West: A Guidebook for Municipal Planners (forthcoming), which will be available through Western Resources Advocates, www.westernresource.org/landuse.
Links to previous posts in the Zoning Centennial’s Series:
Part 8: Regionalism and ‘Wistful Hoping’
Part 11: Designing Density
Part 12: Green Infrastructure
Part 12B: Land Use and Energy Conservation
Part 14: Transit Oriented Development
Part 15: Zoning in Solar and Clean Energy