The document discusses indicators for monitoring progress on SDG Target 6.4 related to water use efficiency and scarcity. It describes the definitions, methods of computation, data needs and interpretation for two indicators - 6.4.1 on change in water use efficiency over time, and 6.4.2 on level of water stress as measured by freshwater withdrawals as a proportion of available resources. Key challenges for implementation include collecting necessary sectoral water use and economic data at national and sub-national levels over time. FAO can provide support through building on existing data collection efforts, working with countries to progressively improve monitoring systems, and compiling global data sets.

1. African Commission on Agriculture Statistics / Commission africaine des statistiques agricoles,
Entebbe, Uganda, 13 - 17 Nov 2017
AGENDA ITEM 4.2:
WATER INDICATORS
Riccardo Biancalani
FAO, CBI

2. Principles for SDG 6 monitoring
 Building on and harmonizing national monitoring
efforts
 Steps of progressive monitoring
 Integration of data
 Policy use and data disaggregation

3. Sustainable Development Goal 6
“Ensure availability and
sustainable management of
water and sanitation for all”

4. Target 6.4 - Water use and scarcity
“By 2030, substantially
increase water-use efficiency
across all sectors and ensure
sustainable withdrawals and
supply of freshwater to
address water scarcity and
substantially reduce the
number of people suffering
from water scarcity”
6.4.1 Change in water use
efficiency over time

5. Target 6.4 - Water use and scarcity
6.4.1 Change in water
use efficiency over time
 National sources: Line
ministries and national
statistics offices
 Progressive steps: national
aggregated values/
estimations  spatial and
sectoral disaggregation 
measured volumes
 Global compilation: FAO on
behalf of UN-Water

6. 6.4.1 Definition and method of computation
This indicator is defined as the value added divided by the
volume of water used, in USD/m3, over time of a given
major sector (showing the trend in water use efficiency).
Following ISIC 4 coding, the major sectors are defined as:
 agriculture, forestry and fishing (ISIC 4-A): agriculture
 mining and quarrying, manufacturing, constructions and
energy (ISIC B, C, D and F): MIMEC
 all the service sectors (ISIC E and ISIC G-T): services

7. 6.4.1 Definition and method of computation
 Water use: water that is received by an industry or
households from another industry or is directly
abstracted
 Water abstraction or withdrawal: water removed
from a river, lake, reservoir or aquifer

8. 6.4.1 Definition and method of computation
Computation:
The indicator is computed as the sum of the three
economy sectors, weighted according to the proportion of
water used by each sector over the total water use. In
formula:
𝑊𝑈𝐸 = 𝐴 𝑤𝑒 × 𝑃𝐴 + 𝑀 𝑤𝑒 × 𝑃𝐼 + 𝑆 𝑤𝑒 × 𝑃𝑆

9. 6.4.1 Definition and method of computation
𝑾𝑼𝑬 = 𝑨 𝒘𝒆 × 𝑷 𝑨 + 𝑴 𝒘𝒆 × 𝑷 𝑰 + 𝑺 𝒘𝒆 × 𝑷 𝑺
WUE = Water use efficiency
Awe = Agriculture water use efficiency [USD/m3]
Mwe = MIMEC water use efficiency [USD/m3]
Swe = Services water use efficiency [USD/m3]
PA = Proportion of water used by the agricultural
sector over the total water use
PI = Proportion of water used by the MIMEC sector
over the total water use
PS = Proportion of water used by the service sector
over the total water use

10. 6.4.1 Data needed
GVA = Gross value added of each sector
V = Volume of water used by each sector
It has to be considered that the GVA of the agricultural
sector should take into account only those sub-sectors
that use abstracted water: Irrigation, livestock, nurseries
and aquaculture

11. 6.4.1 Rationale and interpretation
 The rationale behind this indicator consists in providing
information on the efficiency of the economic and social
usage of water resources.
 This indicator addresses specifically the target component
“substantially increase water-use efficiency across all
sectors”.
 This indicator needs to be combined with the water stress
indicator 6.4.2 to provide adequate follow-up of the target
formulation.
 The interpretation of the indicator would be enhanced by the
utilization of supplementary indicators to be used at country
level. Particularly important in this sense would be the
indicator on efficiency of water for energy and the indicator
on the efficiency of the municipality distribution networks.

12. 6.4.1 Rationale and interpretation
 Water use efficiency is strongly influenced by the economic
structure and the proportion of water intensive sectors
 The change in water use efficiency is influenced by both ‘real’
improvements and deteriorations, as well as by changes in
economic and industry structure.
 Key message: Increasing values in time series indicate decoupling
of the economic growth from water use. It does not necessarily
indicate decline in total water use or a reduction of the impact of
water use (see water stress – 6.4.2)

13. “By 2030, substantially
increase water-use efficiency
across all sectors and ensure
sustainable withdrawals and
supply of freshwater to address
water scarcity and substantially
reduce the number of people
suffering from water scarcity”
6.4.1 Change in water use
efficiency over time
Target 6.4 - Water use and scarcity
6.4.2 Level of water stress:
freshwater withdrawal as a
proportion of available
freshwater resources

14. Target 6.4 - Water use and scarcity
6.4.2 Level of water stress: freshwater withdrawal as a
proportion of available freshwater resources
 National sources: Line
ministries and national
statistics offices
 Progressive steps:
Existing data  new
component  spatial
and sectoral
disaggregation
 Global compilation: FAO
on behalf of UN-Water

15. 6.4.2 Definition and method of computation
 The ratio between total freshwater abstracted by all
major sectors and total renewable freshwater resources,
after having taken into account environmental water
requirements
 The sectors are the same than for indicator 6.4.1

16. 6.4.2 Definition and method of computation
Concepts:
 This indicator provides an estimate of pressure by all sectors
on the country’s renewable freshwater resources
 A low level of water stress indicates a situation where the
combined withdrawal by all sectors is marginal in relation to
the resources, and has therefore little potential impact on the
sustainability of the resources or on the potential competition
between users
 A high level of water stress indicates a situation where the
combined withdrawal by all sectors represents a substantial
share of the total renewable freshwater resources, with
potentially larger impacts on the sustainability of the
resources and potential situations of conflicts and
competition between users

17. 6.4.2 Definition and method of computation
Method of computation:
The indicator is computed as the total freshwater withdrawn
(TFWW) divided by the difference between the total renewable
freshwater resources (TRWR) and the environmental flow
requirements (EFR), multiplied by 100.
All variables are expressed in km3/year (10^9 m3/year).
𝑊𝑎𝑡𝑒𝑟 𝑆𝑡𝑟𝑒𝑠𝑠 (%) =
𝑇𝐹𝑊𝑊
𝑇𝑅𝑊𝑅 − 𝐸𝐹𝑅
∗ 100

18. 6.4.2 Definition and method of computation
 Total renewable freshwater resources (TRWR) are
expressed as the sum of internal and external renewable
water resources. The terms “water resources” and “water
withdrawal” are understood here as freshwater resources
and freshwater withdrawal.
 Internal renewable water resources are defined as the
long-term average annual flow of rivers and recharge of
groundwater for a given country generated from
endogenous precipitation.
 External renewable water resources refer to the flows of
water entering the country, taking into consideration the
quantity of flows reserved to upstream and downstream
countries through agreements or treaties.

19. 6.4.2 Definition and method of computation
 Total freshwater withdrawal (TFWW) is the volume of
freshwater extracted from its source (rivers, lakes,
aquifers) for agriculture, industries and services. It is
estimated at the country level for the following three
main sectors: agriculture, services (including domestic
water withdrawal) and industries.
 Freshwater withdrawal includes surface freshwater,
groundwater and fossil groundwater.
 It does not include direct use of non-conventional
water, i.e. direct use of treated wastewater and direct
use of agricultural drainage water, and it does not
include desalinated water.

20. 6.4.2 Definition and method of computation
 Environmental flow requirements (EFR) are the
quantities of water required to sustain freshwater and
estuarine ecosystems.
 Methods of computation of EFR are extremely variable
and range from global estimates to comprehensive
assessments for river reaches.
 For the purpose of the SDG indicator, water volumes
can be expressed in the same units as the TFWW, and
then as percentages of the available water resources.

21. 6.4.2 Rationale and interpretation
 The purpose of this indicator is to show the degree to which
water resources are being exploited to meet the country’s
water demand.
 It measures a country’s pressure on its water resources and
therefore the challenge on the sustainability of its water us
 Increased water stress, shown by an increase in the value of the
indicator, has potentially negative effects on the sustainability
of the natural resources and on economic development.
 Low values of the indicator indicate that water does not
represent a particular challenge for economic development and
sustainability.

22. 6.4.2 Disaggregation
 The indicator can be disaggregated to show the
respective contribution of different sectors to the
country’s water stress, and therefore the relative
importance of actions needed to contain water
demand in the different sectors (agriculture, industry
and services).
 At national level, water resources and withdrawal are
estimated or measured at the level of appropriate
hydrological units (river basins, aquifers). It is therefore
possible to obtain a geographical distribution of water
stress by hydrological unit, thus allowing for more
targeted response in terms of water demand
management.

23. Discussion
What do you consider to be the most
important challenges for the implementation
of this/these indicator/s?

Which kind of support do you think FAO can
provide to overcome these challenges?

24. FOR MORE INFORMATION, PLEASE CONTACT:
INDICATOR 6.4.1 AND INDICATOR 6.4.2
RICCARDO.BIANCALANI@FAO.ORG
JIPPE.HOOGEVEEN@FAO.ORG
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