The city of Sullana is located on the banks of the Chira River, near the northwest coast of Peru, and is the capital of the district and province of the same name, in the department of Piura.
The urban area is made up of three districts. Two districts, Sullana and Bellavista, are completely absorbed within the conurbation, and one, Marcavelica, only partially. In terms of climate, summers are hot, muggy and cloudy and winters are dry, windy and mostly clear. However, heavy rainfall occasionally causes flooding due to a lack of urban drainage system capacity.
The Peruvian government has undertaken the necessary actions to protect the districts of Sullana and Bellavista from flooding through the Authority for Reconstruction with Changes (ARCC), responsible for leading and implementing the Reconstruction Plan for all the physical infrastructure damaged and destroyed by the El Niño weather phenomenon. TYPSA was engaged by Benito Roggio e Hijos, S.A., the company managing the project, to provide consulting services for the design of the Sullana Integral Stormwater Drainage Project in the districts of Sullana and Bellavista.
Flooding is caused by the overflowing of four main streams: Cieneguillo, Bellavista, Cola de Alacrán and El Boquerón de Núñez. The aim of the project is to protect an area of 828 ha from flooding by improving and expanding the existing drainage system. The drainage system design involves the repair, adaptation, upgrade and improvement of drains, channels, sub-collectors, catchments, discharges and retaining structures for flood control. A population of almost 300,000 will benefit from these actions.
A technical solution known as a ‘Profile’ has been prepared at the level of conceptual design, proposing both structural and non-structural measures to meet the needs. TYPSA’s consulting services include validating this solution and proposing other possible alternatives, ruling out those that are not viable after a multi-criteria analysis, and developing the chosen solution at detailed design level.
The structural measures to be addressed include the following:
- A flood mitigation dam, called ‘Cieneguillo Flood Mitigation Dam’, to reduce the peak flows that currently discharge from the Cieneguillo stream to the ‘Canal Vía’, which is the city’s main drainage structure.
- Upgrade of the ‘Canal Via’, with actions aimed at increasing its water transport capacity, repairing damaged sections, making the connection with the ‘Cieneguillo Dam’ and ensuring the appropriate discharge of its flows to the Chira River.
- ‘Cola de Alacrán’ drain system with independent discharge to the Chira River.
- Cieneguillo Flood Mitigation Dam discharge via a lateral spillway, which evacuates peak flood waters toward the ‘Cola de Alacrán’ drain system.
- ‘Boquerón de Nunez’ drain, built over the existing drain, to carry water from the Bellavista and El Boquerón streams, discharging directly into the Chira River.
- Secondary drainage system to allow drainage in areas where the relief causes areas of depression and where water collects during the rainy season.
At the same time, a series of non-structural measures have also been proposed, aimed at making better use of the structures once they are completed. These measures include drainage system operation and maintenance plans, public awareness plans, solid waste collection system improvements and integration with the structural development of green and leisure areas, thereby enhancing their maintenance.
TYPSA is delivering the following services in this project:
- Preliminary studies, collecting background information
- Preparation of the hydraulic drainage model
- Study of alternatives
- Detailed design of all the structures of the selected alternative
- Development of technical specifications for the tender of works.