SPANISH TOWN, ST. CATHERINE JAMAICA
This presentation is aimed at emphasizing the importance of an effective community flood alert component of Community Flood Warning Systems (CFWS) in vulnerable communities of small island developing states (SIDS), and prioritizing expenditure on Comprehensive Disaster Management in the development process.
The Rivoli and Thompson Pen communities - located on the eastern and western banks of the Rio Cobre respectively, approximately 3 kilometers below the Rio Cobre irrigation Dam - Approximately 20 kilometers from Kingston - Approximately 450 homes and 5000 residents living within the 100yr flood boundary - Major flooding events have occurred 14 times in 54 years (1958 2012) with an average of one flood every 3 years.
Rivoli Thompson pen
The Rio Cobre drainage area covers 520 km 2 consisting of steep sloping mountains, rolling hills and plains. There are 5 major tributaries of the Rio Cobre that drains the upper basin. These tributaries usually generate peak flood flows at varying times during a rain storm causing unpredictable flooding conditions in the Rivoli and Thompson Pen communities. Real Time and Community Flood Warning Systems have been implemented and upgraded in the Rio Cobre Basin by the UNDP since 1989 but the Community Food Warning Component did not include an electrical alarm device. Based on a request from the community a Flood Alarm System was funded and installed by Help Age International in November 2012.
PREDICTION- Forecast of Advance Weather Systems DETECTION- Monitoring of Rainfall and River Levels COMMUNICATION - Relaying Messages by various means DECISION MAKING - Take action based on established criteria MOBILIZATION - Decision on program for evacuation
The initial Community Flood Warning System includes the installation of colour coded flood gauges with blue yellow and red colours indicating Normal Alert and Critical flood levels. Flood level thresholds are set for each of the above levels and actions to be taken documented and circulated within the community. The established alert rainfall depth in the upper Rio Cobre basin that will cause flooding is 100mm (4 inches) in 6 hours. The flood level at the beginning of the gorge that will cause flooding is 2.6 meters (8feet). This information is transmitted in real time to computers and cell phones of selected monitoring officers at the Water Resources Authority and the ODPEM who then communicate the information to the Parish Disaster Coordinator and the communities.
In 2012 the residents of the communities of Rivoli and Thompson Pen requested the installation of an Alarm System based on the following justification. Some residents were not alerted in a timely manner during major floods. Most floods occur at nights when residents are asleep. Localized flooding may occur resulting from rainfall and flood levels not detected by the real time monitoring system. Residents can be alerted by alarm without endangering the lives of gauge readers who has to monitor flood levels at night. The river could reach the critical level several times in one day while complacency could set in after the first flooding event. The community is alerted without dependence on runners or cell phones. The community will provide a location for installation of the alarm equipment at a home where it is secure and properly maintained.
The main purpose of the alarm system is to enhance the existing community flood warning system in a way that will ensure that: - the alerts or warnings reach the most vulnerable in a timely manner. Note: It is not meant to replace the original system.
The Flood Alarm warning system is designed to alert citizens of a possible threat of flooding in or out of the hurricane season. The system is controlled electronically and includes devices that require periodical maintenance and testing. Components 12v relay Solar panel 12 v rechargeable battery Electronic key switch (Howler disabler) Test push button switch Electronic howler Water sensor switch Operation
The water sensor is fixed within a metal housing near the community flood gauge located on the bank of the river. When the river level rises,the sensor reads the water level and sends voltage to the control panel.the control panel then takes the information and forwards it to the howler located beneath the eve of the building to produce the alarm. The 12 v battery provides power to operate the circuit and the howler, while the solar panel maintains a trickle charge to the battery.
To alert the Rivoli and Thompson Pen community especially at nights when flooding may suddenly occur. Note: - The Howler is activated when the flood gauge level of 7ft is breached. -The alarm can be turned off manually by a key attached to the control box -The community will decide the frequency and duration of the alarm sound
Plate 14: Installing Alarm Sensor Cable Plate 15: Alarm System Box Plate 16: Float Sensor Switch
Plate 17: Solar Panel and Howler Siren Plate 18: Testing the Alarm System
CHALLENGES Acceptance and ownership of the system Community willingness to participate Sustainability and maintenance of the system Adequacy of monitoring network and communication system BENEFITS OF FLOOD WARNING SYSTEM Improves the awareness of the community about flooding so that they are better able to anticipate and respond to future flood. It lengthens the lead time before a flood so that the community can adequately provide for evacuation if necessary. Save lives and reduce the cost of damage to property. Promotes community integration and participation Promotes a change of culture and environmental awareness. Improves cooperation among agencies and enhances private and public partnership. Improves security and provide social trust.