In theory water conservation represents one potential "source" of water for Rockland County, in the sense that future demands could be met in part by using less. The information on Water Use in Rockland County on this website gives us some indication of the potential for future demand reduction.

Two case examples below show what’s possible – New York City reduced per capita consumption 39% between 1979 and 2006, while Cary, North Carolina, suburban like Rockland County, reduced its per capita residential water consumption by 15% from 1996 to 2007.

Conservation measures in Rockland County and beyond

Rockland County imposes mandatory conservation measures during declared droughts; the required measures are described in this table for each category of drought declaration.

Requests for voluntary conservation were made in 1981, 1982 and 1985 before Article V of the Rockland Sanitary Code was promulgated. Because of low rainfall the Rockland County Bureau of Water Supply was in intense observation mode during the summers of 1991, 1993, 1995, 1997, 1999, 2001, 2002 and 2005. Mandatory water restrictions were called for in connection with drought emergencies in 1995, 1999 and 2002.

United Water of New York provides water conservation information and guidance for its customers on its website — http://www.unitedwater.com/conservation.aspx — in three areas: low-water landscaping, leak detection and water saving tips for both indoors and outdoors use.

In addition water conservation products are offered at a discount through United Water's partnership with Niagara Conservation. United Water’s conservation efforts began in 1992 when it was still the Spring Valley Water Company. In 1993-1994 24,000 households acquired water conservation devices.

In the past two years 5,000 Niagara Conservation kits have been purchased by United Water customers. The indoor kits contain a toilet dam, low flow nozzles and showerheads, a shower timer and dye to identify toilet leaks. The outdoors kit contains low flow hose nozzles and a hose repair kit, a rain gauge, a moisture meter and a hose timer.

As an added aid to reducing outdoors water use United Water has developed a program to distribute information on regional evapotranspiration rates (ET) during the summer on a weekly basis, advising residents on how many minutes in an hour a lawn should be water given the specific temperature, humidity, wind, rainfall and solar radiation.

United Water’s long-term water supply plan for Rockland County does not, however, incorporate water conservation as a component with expected results. While it recognizes that additional conservation programs will reduce demand, it notes that it has no authority to mandate or enforce water conservation practices.

Case Study: Cary North Carolina

Cary, North Carolina (2006 estimated population of 112,414, annual precipitation of 46.5”) a growing, largely residential suburban area in North Carolina, provides an example of the institution of an ongoing, many-faceted water conservation program with demonstrated success, a 15% reduction in residential water consumption from 1996 to 2007.

Cary is a rapidly growing suburban area west of Raleigh. As in Rockland County, water usage is dominated by single family residential use. To meet increased demand, especially peak demand during hot dry summers, Cary town officials began developing a 30 year water system expansion plan in 1995. As part of this process Cary town officials adopted a water conservation program in 1996 with the goal of reducing average per capita water use by 20% by 2015. Additional goals were the provision of safe reliable water service, conservation of a limited natural resource, and the reduction of infrastructure expansion costs.

In 1999 Cary refocused its conservation programs on ways to reduce peak day demand during the summer. The choice of measures to include in the conservation program was based on a benefit/cost analysis and community acceptance, with each measure needing to meet “significant” cost savings and “reasonable” cost outlay requirements as well. The resulting program has eight elements:

To date the city has been able to delay its two water plant expansions. The water reclamation facility is expected to cut future peak demand for non-reclaimed water by 8%. The weather-adjusted annual average residential gallons per capita per day dropped 15%, from 75gpcd in 1996 when the program was instituted to 64gpcd in 2007.

(Source: EPA, Cases in Water Conservation, 2002; personal communication, Marie Cefalo, Water Conservation Coordinator, Town of Cary, North Carolina, 2008).

New York City Water

New York City, Rockland County’s neighbor, is one of the great water conservation success stories. Many of the lessons learned in New York City can be applied to Rockland, although some aspects of conservation in a highly urban area are not applicable to the more suburban setting in Rockland County. Per capita water usage in New York City has declined by 39% in the last thirty years.

New York City water usage peaked in 1979; the city reduced consumption by 28% between 1979 and 2006, and by 5% between the drought in 2002 and 2006. Between 1979 and 2006 the population of NYC grew 15% (7.1 to 8.2 million people) while water usage dropped by 28%. (New York Times, 10/03/06). This remarkable decline in water usage is due to:

• An extensive leak detection program including computerized sonar leak detection for all city water mains. This program saves 30-50 mgd water.

• Metering of water use by apartment buildings. This program was expanded in 1985 and extended to unmetered residences in 1991. Water metering conserves 200 mgd.
• Low water use toilets. An aggressive rebate program which increased the rate of replacement cost about $290 million, and accomplished an average reduction in water use of about 54 gallons per day per toilet. Toilet replacement has saved about 70-80 mgd water.
• Homeowner inspections (saving about 4 mgd)
• Replacement of other water fixtures such as shower heads, faucets, and appliances with low-flow fixtures and appliances.
• Locking fire hydrants to prevent summer recreational use.

For 17 water conservation case studies see Cases in Water Conservation

Water Conservation in NYC — By the Numbers

The success of New York City's efforts to achieve improved water use conservation over the past three decades was a major achievement in managing municipal water supplies, especially in light of the concurrent increase in population over the same period of time. More details are provided here about some of these changes in aggregate water use in NYC. Documentation is provided in text and tables on one of the NYC web sites related to drought occurrences in the past three decades.(Table of total annual NYC water consumption and per capita water consumption:1979-2006)

The table of water consumption provided by NYC Department of Environmental Protection on this web site reports total daily average (calendar year) water use in NYC in million gallons per day and also average annual per capita water use in gallons per day for the years 1979-2006. The highest total daily water use was 1512 million gallons per day (1979) and the lowest total daily water use was 1069 million gallons per day (2006). Per capita daily water use for the same period had a maximum value of 208 gallons per day per capita (1988) and a minimum value of 134 gal/d/cap (2006). These data clearly illustrate the large decrease of per capita water use in NYC since 1979 (~36%)..

NYC populations for each of the years between 1979-2006 were not reported in the table on the NYCDEP web site, but can be derived directly from the total water use and per capita water use data. These computed population data are not identical to data reported for NYC population by the US Census Bureau and several of their web sites. We do not know the source of the NYC population data used by NYC DEP and they appear to have some obvious inconsistencies. For instance, the computed population for 1980 was 8.01 million and for 1981 was 7.22 million. It seems unlikely that the total population of NYC declined by 10% (~800,000 people) in a single year.

We chose to construct our own estimates of NYC population for the years 1979 through 2007 to permit calculation of a revised set of per capita daily water use values. (click here for details of our approach)

After construction of an annual time series of NYC population for 1979-2007, we then combined these population data with the values of NYC water use from the NYC DEP web site on drought history, and then calculated a new set of per capita average daily water use for the years 1979-2006. The maximum value of per capita water use was 213 gallons per day (1980) and the minimum value was 130 gallons per day, indicating a total decline of 39% over a period of less than 30 years. This is a remarkable achievement, and was equivalent to a daily savings of 83 gallons per capita or ~685 million gallons per day for a NYC population of 8.25 million (2007). Almost 700 million gallons per day of water use conservation is equivalent to the total daily delivery from some of the largest water supplies in the US to major urban centers.