Water Resources in Rockland - Planning in a Changing World

Water Conservation

low flow showerheadIn 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.


Stage 1

Drought Watch


  • Restaurants can’t serve water unless a patron asks for it
  • Ornamental water uses (fountains) must be turned off unless they use recycled water
  • Sewers and hydrants can’t be flushed unless it’s immediately necessary to protect public health and safety
  • Lawn watering is limited to certain days and hours
  • Lawn watering is banned if there has been 1/8” of rain in the preceding 24 hours
  • Export of water outside the county is prohibited
  • All water leaks must be repaired within 48 hours
  • If Stage 1 last 30 days all commercial and industrial users must submit a conservation plan to the Rockland County Dept. of Health

Stage II

  • All prohibition and requirements of a Stage I Emergency apply
  • Nursery and golf course irrigation is limited to 90% of average monthly use
  • Washing non-public paved surfaces (e.g., patios, sidewalks, driveways) is prohibited.
  • Non-commercial washing of vehicles is prohibited
  • All commercial and industrial water use (including commercial vehicle cleaning) is limited to 90% of average monthly use

Stage III

  • All prohibition and requirements of Stage I and Stage II Emergencies apply
  • Washing of all paved surfaces, including roads, is prohibited.
  • Nursery and golf course irrigation is limited to 80% of average monthly use
  • All commercial and industrial water use (including commercial vehicle cleaning and the commercial use of water or steam for the cleaning of building exteriors and decks) is limited to 80% of average monthly use
  • Watering public athletic fields, landscaping and non-agricultural gardens is limited.
  • Lawn sprinkling is prohibited
  • Non-commercial use of water or steam for the cleaning of building exteriors and decks is prohibited
  • Filling of recreational swimming pools is limited.
  • Use of non-recycled water for commercial vehicle cleaning is limited

Stage IV

  • All prohibition and requirements of Stage I, Stage II and Stage III Emergencies apply
  • All commercial and industrial uses are limited to 75% of their average monthly usage, including commercial cleaning of building exteriors, commercial cleaning of vehicles, golf course and nursery irrigation
  • Filling of swimming pools, irrigation of landscaping and non-agricultural gardens is limited.
  • Use of water from any stream, creek or other surface supply is prohibited
  • Watering public athletic fields is prohibited
  • Use of non-recycled water in water-cooled air conditioning units os prohibited
  • Fountains and other ornamental water uses must be shut down

Stage V Severe Drought Emergency

  • All prohibition and requirements of Stage I, Stage II , Stage III and Stage IV Emergencies apply
  • Residential water usage is restricted to 50 gallons per capita per day (gpcd) or to 70% of average winter use.
  • Agricultural uses are prohibited in excess of the average daily consumption for the preceding 12 months.
  • Use of swimming pools and ice rinks is prohibited, as is the irrigation of landscapes and non-agricultural gardens
  • Use of water for cleaning building exteriors and the use of recycled water for washing vehicles is prohibited,
  • Watering of golf course greens by hand is limited to once per day.
  • Nursery irrigation is limited to 2 hours per day.

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.

From May through August United Water charges higher rates for water in a further effort to dampen discretionary summer usage.

United Water’s long-term water supply plan for Rockland County does not, globalhowever, 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.

Rockland County water conservation case study presented at American Water Works Association Water Conservation Symposium: read the full paper.


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:

In 2010 Cary NC undertook an analysis of water use from 2001-2009. The table below provides a snapshot of average indoor water usage in categories based on the age of residence. Notably, homes built between 2001 and 2005 averaged 50 gpcd indoor usage and since 2005 the average has dropped to 43 gpcd, presumably from the use of water-efficient washing machines. For comparison, Rockland County indoor water usage from 2000-2009 is estimated to have averaged 62 gpcd.

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.

  1. Public education (includes a "Beat the Peak" program, grassroots neighborhood programs, elementary and middle school programs, workshops to reach water-efficient landscaping and gardening)
  2. Landscaping and irrigation codes (city regulates irrigation and commercial landscaping)
  3. Toilet flapper rebates (early closure flappers save 1.3 gallons/flush)
  4. Residential audits (free 1 hour audit)
  5. Conservation rate structure (increasing block rate structure to encourage conservation)
  6. New home points program (credit in development approval process for use of water efficiency measures, not implemented yet)
  7. Landscape water budget (for large public and private irrigation users, and, on request, for residents with larger than average lots)
  8. Water reclamation facility (for irrigation and approved non-potable uses, free to bulk purchase customers)
(Source: EPA, Cases in Water Conservation, 2002; personal communication, Marie Cefalo, Water Conservation Coordinator, Town of Cary, North Carolina, 2008).

Year Residence Built # of residences Avg. Indoor gpcd
<1975 3,688 49
1975-1994 14,815 58
1995-2000 8,090 59
2001-2005 4,792 50
>2005 5,246 43
Weighted average, all years 36,631 54

New York City passes four new laws addressing water use efficiency on October 13, 2010. Click here for details.

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.


The history of NYC water use over the past three decades shows that conservation through sustained cooperation of municipal government and citizens over decades can accomplish major reductions in average daily water use. The result is very large savings in expenditures for operation, maintenance and capital investments. We hope this message of the potential for conservation of municipal water supplies in future management of systems outside NYC can stimulate major improvements in use efficiencies for suburban municipal water supplies. The supply of tax and other revenue sources, as well as energy resources, to provide high quality municipal water will be under increased pressure from competition with other critical service needs in the future.

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