“Efficiency is Cheaper than Fuel”

 by Bryan Bates

The title of this article is a quote from Amory Lovins.  Lovins, the winner of the 2007 Leadership Breakthrough Award from Popular Mechanics is the executive director of the Rocky Mountain Institute which has a special focus on profitable innovations for energy and resource efficiency

"Efficiency," Lovins told an audience at Popular Mechanics' Breakthrough Conference in October 2007 at the Hearst Tower in New York City, "is cheaper than fuel."

While you may not see water as a “fuel”, the water users such as hydroelectric power generators do.  Water also fuels the growth of grass for dairy farms in parts of the country, the wide variety of crops in the horticultural industry, as well as keeping us all alive and healthy through private and municipal water supplies.

In a recent review of a municipal water supply strategy, I was amazed how little information there is about benchmarking efficient water use.  Sure there are studies for irrigation water demand in various parts of the country, and the ANZECC guidelines provide various levels of water demand for animals, but when one drills deeper (sorry for the pun) to find the source of some of these numbers, the science (except for some irrigation work) is very thin.

Water supply operators spend a lot of time and money ensuring adequate supplies are available (using data provided by Hydrologists), but in many parts of the country, water demand has now equalled or exceeded these sources.  Therefore it surprises me how little knowledge there is of benchmarks for efficient water use.

A good example is “Unaccounted for” water in municipal supply systems.  Check out a few Asset Management Plans published by various Territorial Authorities, and you will find that huge amounts of water “disappear” from public supplies.  Yes some of this may be for firefighting and illegal connections, but this does not account for the majority of this loss.  

In 2004 the Ministry of Economic Development Infrastructure Stock take: Infrastructure Audit (Published on 01 Jan 2004) showed that the average of 13 Territorial Local Authorities in New Zealand measure leakage to be 161 litres/connection/day.  The average percentage of Unaccounted or non-revenue water for the councils surveyed was 16% (varying from 9.4% to 29.6%).  A recent investigation into a small town water supply I have seen found 39% of the water supply was unaccounted for!
For Domestic use in urban areas, the Ministry for the Environment in 2000 identified a variety of values for reasonable domestic use (see “Information on Water Allocation in New Zealand” Report No. 4375/1, April 2000).  Measured rates for Whangarei City were 180-225 litres per person per day, for small Northland towns 400 litres per person per day, and for Christchurch, household use was 800-900 litres per day.  

This lack of definitive water use efficiency data must make it difficult for Regional Councils processing resource consents to take water.  What is the basis of their allocations to various applicants?  Are they based on monitoring results of already inefficient systems?  Do they just trust consent applicants estimates of their needs without comparative benchmarks?  If so this could result in water being allocated to wasteful users.

So what is needed?  

Well my opinion is that a comprehensive national guideline for benchmarking best practice for water use is required.  This should cover a wide range of uses and industries.  The Ministry for the Environment should be driving this as a part of their function, particularly the Sustainable Water Programme of Action.

A comprehensive review of all the national and international literature will be necessary.  This would provide a snapshot of what guidance is already available.  

A gap analysis would show what needs to be done in terms of further data collection and analysis.  An example of further work would be simple water balance monitoring of a number of dairy sheds throughout the country.  Right now I can’t find anyone who can provide me with a scientifically based quantity required for dairy shed operation for different herd sizes in different parts of the country, despite a boom in the dairy industry increasing water demand.

A national guideline would also update documents such as the Auckland Regional Council Technical Publication 55 “On Site Wastewater Systems: Design and Management Systems” which has a comprehensive domestic water use section for various levels of appliance efficiency.  As technology is advancing, so is the efficiency of various water using appliances and ongoing updates of databases will be required.

Throughout the country, water supplies are coming under stress from high demand.  Many water users are finding it is more cost effective to reduce demand than to find new “fuel” by developing new water supply infrastructure.  A national guideline is therefore urgent and essential to provide a consistent and cost effective approach to bench marking efficient water use best practice.

About the author:  Bryan Bates is the Principal of Cirrus Associates Ltd (cirrusassociates@xtra.co.nz), a consultancy specialising in strategic planning and resource consents for water supply, wastewater, stormwater, and coastal water.

This article was printed in the NZ Hydrological Society newsletter "Current" in November 2008.