Floods in Durán: the most vulnerable sectors and solutions based on nature, according to an Espol study

Friday, 5:00 p.m., the last rays of the sun, attenuated by cloudiness, are reflected in the accumulated water that exceeds the level of the streets and sidewalks in the five stages of El Recreo, in the northeast of Durán, a sector that had woken up flooded by “ the rain of a month that fell in a single day”, due to “the aguaje that occurs this week on the Ecuadorian coast”, due to “the lack of dredging of the Guayas River”, as justified by Mayor Dalton Narváez.

It’s been seven hours since it stopped raining, but the houses in El Recreo continue to drain the water, which has nowhere to go because “people throw garbage and cover the drainage canals,” because “the level of the Guayas River, due to the high tide and the sediments, it is 70 cm higher than the natural drainage channels and forms a plug”, adds Narváez, who has arranged to redouble the cleaning of the ditches that border this populous sector, surrounded by cooperatives that have been born from the land invasions, where there are no basic services.

Night is coming and all that remains is to wait for the water to subside and for it not to rain again in El Recreo and its surroundings, identified in a study by the Espol Pacific International Center for Disaster Risk Reduction as the lowest areas in the topography of Durán and therefore with higher probabilities of flooding. Contrary to what the locals expect, it rains again.

“When we start the project Climate Resilience for Durán We analyze floods, heat islands and landslides in the hills. Durán is the perfect example of a city that is exposed to all these climatic events”, says professor and researcher at Espol Mercy Borbor.

The academy, in this case the Espol, has been collaborating with this study in Durán since 2018 and has provided information to the previous and current municipal administration on what are the vulnerable areas, but also what are the solutions adopted in other coastal cities that could be run here.

the lowlands

The northern quadrant, especially to the east, where El Recreo, 5 de Junio, Oramas González, Gregorio 2, San Genaro, the 288-hectare sector and other surrounding sites are located, have been identified in the Espol study as the with greater impact due to the sum of natural and anthropic factors (man’s action).

The main factor, says Dr. Borbor, is that this is a low-lying area that, before being filled in by human action, was a large wetland. Another aspect that affects flooding is the type of soil, which is clayey. “This forms a compact mass that quickly becomes saturated and does not allow water to infiltrate into the subsoil.” There is also the high impermeability, once again, due to the human factor.

In El Recreo, as well as in other citadels of Durán, its inhabitants have gradually paved the flower beds that divide the pedestrian streets and the water does not filter naturally, but must drain into a sewage system that was not designed to bear all that it receives.

This housing plan, created in the mid-1990s, was one-story houses with two rooms, recalls the director of the Climate Resilience project for Durán. But now, there are few original houses left, not having much land, the growth was upwards. “Population growth went from single-family homes to three-story buildings.”

And in the surrounding areas the situation is worse, the so-called ‘invasions’ -which are not part of the municipal urban planning- do not even have a sewage system.

What solutions proposed in other coastal cities could be replicated in Durán?

The Espol project proposes three types of solutions:

The first is to favor the drainage of housing areas towards open channels and areas destined for water to accumulate (flood basins), for example, around the canals, zones can be created that have been converted into linear parks, flood basins into parks and areas destined for mangrove ecosystems or vegetation that help capture water on the banks of estuaries or natural channels such as El Matanza, San Enrique, 5 de Junio ​​and San Camilo.

The second approach, says Borbor, is to build rain gardens throughout the city where possible, avenues, flower beds, pedestrians, to capture water during the rains and infiltrate them into these spaces. “Each rain garden can store between 7,000 and 10,000 gallons of water, depending on the design.”

These solutions can be planned, designed and built in different parts of the city and guidelines and regulations can be established to promote their implementation. They are cost-effective and highly effective in reducing runoff water in urban systems, but require proper technical design and low maintenance. In addition, they reduce erosion, sedimentation and finally help improve the quality of the water before it reaches the Guayas estuary.

And lastly, solutions for capturing rain in homes are proposed, which while reducing the amount of water that runs off through the streets and sewers, allows the inhabitants, especially in areas where there is no piped water service, to , can have rainwater for washing and use in bathrooms and gardens. “40-gallon blue tanks can be placed in drop ceilings. These initiatives can be supported by private companies and climate change adaptation programs in cities”.

But for all this financing is needed and the Municipality of Durán is going through a difficulty. You must pay a loan of more than $ 32 million that was not reimbursable, but that became so when the previous administration did not comply with the project for the “improvement and optimization of the drinking water conduction system”, which is being investigated by the Prosecutor’s Office after a report from the Comptroller.

Be that as it may, Borbor warns, “we have to prepare ourselves to live with an increasingly extreme climate, so the development of Early Warning Systems is important, which help us understand floods and prepare ourselves in different aspects when they occur” . (I)