Flood Control for the Lake Managua Watershed
Imagine going through every rainy season worrying that a flood will damage or destroy your home. That was the situation for some of the people living in the southeastern area of the Lake Managua Watershed, known as Sub-Basin III. The area includes the capital of Nicaragua and the municipalities of Ticuantepe, El Crucero, La Concepción, and Nindirí. Together these localities are home to more than 220,000 people.
Over the past 15 years the area has had to deal with deforestation, unplanned urbanization, and changes in crop management. Among other problems, these developments resulted in soil erosion that made the terrain less usable for sustainable agricultural production. Another serious consequence of the erosion was that it impeded rainwater from filtering into aquifers, endangering the water reserves that supply this basic service to a large portion of Managua’s population. Instead of filtering, the rainwater ran toward the low part of the watershed, carrying with it all types of solid residues and increasing the risk of flooding.
To address this problem, the government of Nicaragua and the IDB agreed in 2009 to design a program to mitigate the risk of flooding and run-off by building works for storm drainage and for better management of solid residues. The program, financed by a US$13 million IDB sovereign-guaranteed (SG) loan, also aimed to reduce soil erosion and promote land-use planning with an environmentally responsible focus.
The results of project activities, which concluded in 2014, included reducing the number of people at risk of flooding. The program also reduced the area susceptible to floods by 177 hectares; increased the capacity for solid waste collection by 40 percent; implemented measures to reduce erosion; and designed environmental and development management plans for the municipalities in the area.
A year after the project was completed, in 2014, the rains arrived once again with the winter season. The area where the new storm drainage works had been built was protected from the devastation that affected surrounding areas, proving the effectiveness of the infrastructure that was financed.
This project exemplifies the fundamental importance of having strong and coordinated institutions. The municipalities in the affected area established an association to jointly address the problems of the Sub-Basin and benefit their local communities.
In addition, the project’s institutional strengthening activities included the creation of an Environmental Management Unit in each municipality. These units played an important role in handling such tasks as detecting deforestation activities and illegal garbage dumps, assessing environmental fines and sanctions, and promoting environmentally responsible agriculture. In this way, the project contributed to strengthening the capacity of local authorities to better manage the Sub-Basin.
Continue reading Chapter 2 - Infrastructure for Competitiveness and Social Welfare