Management of an urban lagoon. Study case: Ilusiones Lagoon, Tabasco, Mexico

Abstract

As a delta, Tabasco, located in the Mexican southeast, is susceptibleto flooding. The city of Villahermosa, the capital of Tabasco, is not an exception. Themost recent event occurred in November 2020, when an excess of rain provoked anurban lagoon to exceed its levels. The lagoon discharges at a river by a diversionchannel controlled by a culvert. To analyze it, a hydraulic model -HEC RAS V6.0-was used. The precipitation, flow, and level data recorded during 2020 were usedto simulate four scenarios: I) one culvert of 1.5 m x 1.75 m (current situation); II)three culverts of 1.5 m x 1.75 m; III) three culverts of 2 m x 2.5 m; and IV) oneculvert of 10 m x 2.5 m. The dimensions of the culverts were subject to the availablephysical space of the discharge channel. It was found that the best performancewas achieved with scenario II. This result is contrasting because this alternative isnot the largest as might be expected; it is also encouraging because it improves theperformance of this lagoon. With this proposal, we reduce the damage by 75.31%,which means 296 homes are protected. Finally, the proposed methodology canguide designers and decision-makers to evaluate hydraulic works in urban lagoonslike those presented in this work.