“Water Supply & Distribution

in Barbados”

March 24, 2016

Presenter:

Charles Leslie, Project Manager (NRW Reduction Unit)

Water Supply & Distribution in Barbados

Account of World’s Water Resources

Available Water Resources of Barbados

Country Classification

Hydrogeology of Barbados

Water Supply

Source

Available Water Resources

Water Quality

Groundwater Protection Policy

Water Distribution

Water Supply & Distribution Challenges

Responses to Challenges

Account of World’s Water Resources

Saline water 97.2%

Freshwater 2.8%

Water in Land Areas

Ice Caps & Glaciers * 2.14%

Groundwater (to depth of 13,000 (4,000m)) 0.61%

Soil moisture 0.005%

Freshwater Lakes 0.009%

Rivers 0.0001%

Saline Lakes * 0.008%

•Only a small percentage of the world’s total water supply is available to humans as freshwater

Available Water Resources of Barbados

Annual Internal Renewal Water Resources (WRM&WLS 1997) – Total 82

million m3 (approx. 49.4 MGD)

Groundwater derived from infiltrated rainfall accounts for 90 %

Surface water accounts for 7 %

Springs account for 2.4 %

Direct runoff to the sea accounts for 0.6 %

Country Classification (based on availability of water)

Countries with annual internal renewable water resources (IRWR) availability of less than 1,000 m3/capita/yr have been classified as water scarce

Barbados has IRWR of 350 m3/capita/yr

Barbados has been classified by the UN as one of the 15 most water scarce (stressed) countries in the World

Majority of severely water stressed nations on the UN list are located in the Middle East and the Caribbean

(Based on 1990 Population, Average Annual Rainfall)

Ref.: Water Quality and Conservation, by Raymond Reid, Division of Health

and Environment, PAHO; paper presented at the Health and Environment in

Sustainable Development Workshop, 16 April 1994

350

5500

4200

2800

5000

3300

3250

1800

1900

0 1000 2000 3000 4000 5000 6000

CUBIC METRES

BARBADOS

ST. LUCIA

TRINIDAD

ANTIGUA

ST. KITTS

JAMAICA

CUBA

HAITI

DOM. REP.

CO

UN

TR

IES

FRESH WATER ESTIMATE

Annual per Capita Allocation

Hydrogeology of Barbados

85% karst limestone formation, 15% Scotland District Oceanics

Source

The source of all our fresh water resources (Barbados) is rainfall. Some of this water is either trapped above the ground in surface impoundments (surface runoff), or infiltrates deep into the coral rock to become groundwater.

Available Water Resources

The amount available for use is dependent on a number of climatic and hydrologic conditions (e.g. 2015 rainfall was lowest recorded in 74 years)

80% of the rain is lost through a combination of evaporation and transpiration (i.e. Evapotranspiration)

In Barbados the available conventional water occurs in three modes:

Groundwater

Surface Runoff

Spring water

Water Supply

Water Quality

Is defined in terms of the Chemical, Physical and Biological

content of the water

Water becomes unsuitable for a specific purpose when either the

chemical, physical or biological constituent levels exceed certain

predetermined allowable levels

The Quality of Water in Barbados is maintained through a number

of factors and measures

Soil Cover

Coral Rock

Groundwater Protection (Zoning) Policy

Water Supply

Groundwater Protection Policy

Early in 1960’s this policy was

implemented to protect the island’s

groundwater resources

The policy delineates the island into

5 zones, with Zone 1 being the most

restrictive in terms of development,

while Zone 5 has no major

restrictions for development

Water Supply

Land area – 430 sq. km (166 sq. miles)

Resident Population – 270,000 persons

Long Stay Visitors (avg. 7 days) – 300,000 p.a.

Short Stay visitors (avg. 1 day) – 500,000 p.a.

BWA utilizes 16 sheetwater wells, 5 streamwater wells, 14 boreholes, 2 Springs

and a Desalination Plant to produce 34MGD of potable water

The network used to distribution potable water to the population >

2000km in length

Pipe sizes range from ½” (customer) to 21” (transmission)

Pipe materials are primarily Cast Iron (CI), Ductile Iron (DI), Polyvinyl

Chloride (PVC) and High Density Polyethylene (HDPE)

Water Distribution

Water Supply & Distribution Challenges

Water Supply

Reduced precipitation, higher than normal temperatures (based on predictions)

Potential contamination

due to changes in land-use, in water catchments

due to over pumping of aquifers (e.g. Salt-water intrusion, aquifer mining)

Increasing water demands

Distribution

Management of Aged infrastructure

Accelerating infrastructural repairs & upgrades

Management of Non-Revenue Water (NRW)

Barbados estimated at 43% (Halcrow 2012), 7% apparent losses + 36% real losses

Non-Revenue Water (NRW)

NRW figures for utilities around the globe

Response to Challenges

Water Supply

Developing & implementing more robust emergency management programmes

Protecting existing groundwater reserves

Encourage Conservation & Recycling

Public Education

Development of additional augmentation alternatives (e.g. seawater desalination, sewage reuse for irrigation and groundwater recharge)

Distribution

Implementing an effective pipe replacement programme

Developing & implementing new NRW programmes

Intensification of leak reduction programmes

Management of pressures in the distribution system

Improving the operational efficiency of the water system

Other Responses to Challenges

By Supplier/ Customer

Timely repairs to leaks

Strengthening of legislation

Use of efficient water use fixtures

Changes in water use habits

Water Supply & Distribution

“Our Fresh Water Resources are Limited,

Let’s Use them Wisely !”

The End