San José, Costa Rica, since 1956

Engineers Study Ways to Reduce Flood Damage

THE Federated Association ofEngineers and Architects (CFIA) hasjoined several government institutions toform a special commission to find ways toreduce damage caused by the floods thatravage the country’s Caribbean region severaltimes a year.The idea of creating the commissionwas proposed by CFIA after conducting apreliminary study of the causes of thefloods.Edwin Patterson, a legislative deputywho represents the eastern province ofLimón for the Citizen Action Party, earlierin the year asked the CFIA board of directorsto conduct the study.Ateam of four engineers conducted thestudy. In addition to theoretical analysis onthe causes of the flooding, the engineersconducted two field visits to observe theBanano, Barbilla, Blanco, Chirripó,Estrella, Pacuare, Pacuarito, Siquirres andSixaola rivers.The increasing frequency of floods inthe Caribbean – up to three times a year insome places – threatens the social and economicwell being of the zone by causingserious damage to the region’s infrastructure– roads, bridges, homes, electrical andphone services, schools and health-carefacilities, according to Olman Vargas,executive director of CFIA.MOST recently, during the secondweek of May, flooding affected parts ofSarapiquí in north-central Costa Rica andthe lowland areas of Limón province,including the town of Matina and the portcity of Limón.Area rivers were engorged by the fallof nearly 600 millimeters (23.6 inches) ofrain in one week. More than 1,000 homeswere flooded, forcing nearly 2,200 peopleinto temporary shelters. The water sweptaway, made impassable or otherwise damaged50 bridges in the region (TT, May14).In recent years, the Caribbean coast hasbeen subjected to an increasing number ofcold fronts caused by the “El Niño” weatherpattern. This has increased the numberof temporales – storms that cause rain tofall continually for more than two days.Within two or three days, constant, unrelentingtemporal rains can deliver on averagebetween 200 millimeters (7.9 inches)and 300 mm (13.5 inches) of water, accordingto the study. In many cases, this isenough to cause rivers to overflow and floodnearby lowlands and wash away poorlyplanned settlements along the banks ofrivers.Toward the end of 2002, for example,the city of Limón received 300 millimeters(13.5 inches) of rain in just one day.The amount of rain received in November2003 marked the highest monthly amountreported during the past 50 years, accordingto the study.THE region’s propensity for floodingwas also increased by the 1991 Limónearthquake, which modified the paths ofmany area rivers. This, in addition to erosionalong the banks of some rivers andobstruction of the natural flow of others bymanmade projects, has worsened the problemof flooding.Residents and businesses have tried toprotect themselves from flooding by raisingthe riverbanks and attempting to change therivers’ paths without taking into account thenegative side effects this could have.“On repeated occasions, the infrastructurecreated to protect against flooding hascaused more harm, rather than the benefitthat was expected,” the report states. “Itshould not be immediately accepted thatcontrolling the flood is the best or the onlyoption [to deal with floods].”The most effective measures, the studystates, are preventive measures, such asemergency plans, improved weather andflooding predictions, alert systems andrestrictions on land use.THE report criticized national andlocal governments for failing to properlyplan and take into account the region’s situationwhen building infrastructure in theregion. As an example, the study mentionedthe road to Matina, which is locatedbetween the Pacuare and Barbilla rivers.Being close to two rivers makes the roadtwice as likely to flood.Most infrastructure has been built tosolve specific problems without taking intoaccount the effects it could have on the naturalflow of rivers. These isolated effortsare not subject to any type of regulation,and suggest a lack of technical criteria andclear policies on how to protect the region,according to the study.In most emergencies, the governmentcreates temporary infrastructure projectsthat end up being permanent, which createsadditional safety concerns, the study states.Damaged infrastructure that is rebuiltis usually rebuilt in its original location,even if the location is prone to floodingand deemed high-risk.“There are protection projects that arecollapsing and aren’t being properly maintained,”said CFIA president IreneCampos. “Each rainy season will contributeto making them further collapse orbecome less efficient. Nothing can be doneabout the climatic conditions. There needsto be planning and proper maintenance ofprojects.”AS immediate measures, the studyrecommended creating a commission thatincludes CFIA as well as the PublicWorks and Transport Ministry (MOPT),the National Emergency Commission(CNE) and the Atlantic Port Authority(JAPDEVA) to issue recommendations tothe government.The study also proposes the creation ofa regional development plan for theCaribbean.Officials also are called on to enforcethe country’s Environmental Code and limitbuilding in regions prone to flooding.The study stresses the need to create adatabase of hydro-meteorological activity –the behavior of rivers in response to weatherpatterns. This would make it easier to planconstruction projects in the region, the studyconcludes.

Comments are closed.