Thematic Session “Integrated Flood Risk Management Through Appropriate Knowledge Sharing And Capacity Building Systems” Kobe, Japan January 20, 2004 Flood Forecasting and Hazard Mapping in

Presenter Andreas Haiduk

Water Resources Authority Jamaica 1 Content • The cause and nature of flooding • Flood warning systems/Hazard mapping as risk reduction instruments. • Lessons Learned • Way forward

2/2/2005 2 Jamaica located; 161 km (100 miles) south of Cuba Latitude 17o42′ and 18o31′ N Longitude 76o10′ and 78o22′ W. .

2/2/2005 3 Cause of Flooding

9 Jamaica prone to flooding Flood prone areas 9 Topography Housing areas /geology determines the 'W$T'W'W $T $T nature of $T$T 'W'W 'W'W'W'W'W 'W'W 'W$T $T $T$T$T $T'W'W'W'W'W'W$T'W$T 'W 'W'W'W'W'W'W'W'W 'W'W'W'W'W'W'W'W'W'W'W'W'W'W $T $T $T 'W'W $T 'W$T'W$T 'W 'W'W'W'W'W'W'W 'W'W'W'W'W'W 'W'W'W'W'W'W'W'W'W'W'W'W'W $T flooding 'W$T$T'W$T$T $T $T 'W'W'W'W'W'W'W'W'W'W'W 'W'W'W $T $T $T$T$T'W$T$T $T 'W $T 'W'W'W'W'W 'W'W'W'W'W'W 'W $T$T 'W'W'W$T $T$T$T $T$T$T$T'W $T $T 'W 'W'W'W'W 'W'W $T$T 9 Climate also 'W'W$T'W'W$T$T$T'W$T'W$T'W$T$T$T$T$T$T $T $T$T 'W 'W'W 'W'W'W 'W 'W$T$T$T$T$T$T 'W$T 'W$T'W $T$T$T$T$T$T$T $T $T $T 'W'W 'W $T$T$T $T$T$T $T $T'W 'W$T$T$T 'W'W'W'W'W'W'W 'W 'W'W'W'W'W'W'W'W'W'W $T impacts 'W$T 'W'W'W'W 'W'W'W'W'W'W'W 'W 'W $T$T 'W$T 'W$T$T'W'W$T 'W'W $T $T'W'W$T 'W'W 'W'W'W'W'W'W'W'W'W'W'W'W 'W 'W'W 'W'W$T $T'W'W'W$T'W'W$T $T 'W 'W $T 'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W 'W$T$T 9 Man’s impact 'W'W'W 'W $T'W'W'W'W'W'W'W 'W 'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W 'W 'W'W 'W'W'W'W'W'W'W'W'W 'W'W'W'W'W'W'W 'W'W'W'W'W'W'W'W'W'W$T'W'W'W'W'W'W$T'W'W'W$T'W'W'W$T'W$T$T $T $T$T $T 'W'W'W'W'W 'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W'W$T$T $T'W'W'W'W$T 'W$T$T'W$T'W'W'W'W$T'W'W$T $T$T aggravate the 'W'W 'W 'W'W'W'W'W'W'W'W 'W'W'W'W'W$T 'W 'W'W'W'W$T 'W'W $T$T'W$T 'W$T'W$T$T$T$T'W$T 'W'W $T $T 'W'W'W'W$T'W'W'W 'W'W$T'W'W'W'W'W'W'W flooding $T$T$T$T$T'W$T'W'W$T$T$T$T$T $T$T$T

2/2/2005 4 Nature of the flooding

• Groundwater induced • Depression • Riverine

• Storm Surge • Urban Runoff

2/2/2005 5 Minimising the Flood Risk

What is the Jamaican Experience ?

2/2/2005 6 Existing early warning systems in Jamaica

1992-NF 1999-D 1993-F

1992-year established NF- not functioning F- functioning D-development stage

2/2/2005 7 Future Early Warning Systems

Pencar River

2/2/2005 8

2/2/2005 9 Flood Forecast table

2/2/2005 10 Flood Forecasting 20 18 16 Rainfall 14 Stage Hydrograph 12 10 Flood Stage 8 Potential additional 6 Warning time 4 2 0 Preparedness Flood Flooding Recovery Preparedness plan plan Recognition Warning time at stage

2/2/2005 11 Community Based Early Warning Systems in Jamaica

FLOOD GAUGES Blue = Watch mode Orange = Alert mode Red = Critical

2/2/2005 12 Value FEWS to Community

Communities Reliability Loss Is System Reduction still being used

Rio Rivoli 97% yes 97% yes 100% Cobre Thompson 93% yes 100% yes 98% Pen

Cave River (Aenon 44% yes 28% yes 60% yes Town) 16% no 39% no 6% no

ODPEM Field Survey February 2004 2/2/2005 13 RECOMMENDATIONS

Get local govt involved and designate a Lead Agency Revive communication process within communities Improve equipment and monitoring Institute annual drills Upgrade /Maintenance of systems Dedicated Budget Strengthen institutional capacity

2/2/2005 14 Flood Plain Mapping •Flood plain mapping Project, WMO 1980s •Hydrologic Support Unit Project UNDP 1990s •Community Disaster based management Projects UNDP, USAID, DIPECHO, 2000s - to date

1 6 1 3 2 4 2 3Hope River 5 4Rio Cobre 5 Rio Minho 6

2/2/2005 15 Overview of the Mapping Process

ArcView ArcView Input Data Flood DEM plain maps

HEC-RAS HEC-HMS Water Flood surface discharge profiles Flood Plain Map

2/2/2005 17 Problems with usage

1. No guidelines for their interpretation and use. 2. No national standard for regulatory flood 3. No national guideline prohibiting/permitting flood plain uses. 4. No national standard for the level of protection – depth/or flow velocity 5. Very limited number of flood plain maps available. 6. No flood zoning done - hence need for rigorous analysis to assess cumulative impacts

2/2/2005 18 Legislative Amendments •Amendment of the Water Resources Act 1995 •Repeal of the Floodwater Control Act 1958

The Water Resources (Amendment) Act, 2003 has been drafted. - Floodwater Control Areas - Floodwater Control Plans for those areas. Flood Control Policy to be implemented (regulatory flood, usage regulation, zoning, etc)

2/2/2005 19 THE END

THANK YOU FOR YOUR ATTENTION 2/2/2005 20