Hydrological study of the stream basin and basements for the purpose of dimensioning a small dam located in the municipality of Crato-CE

Abstract

Dams are fundamental engineering structures for the accumulation and management of water for multiple purposes, such as irrigation, navigation, recreation, human and animal supply, as well as supporting fishing, mainly in rural areas. Historically, their primary function was to ensure water storage during dry periods. Among the various types, earth dams are the most common in rural areas due to their cost and construction feasibility. However, to ensure structural, economic, environmental, and social safety, the development of an adequate technical design is essential. In this context, this study aimed to conduct a hydrological analysis for the design of a small dam in the municipality of Crato, Ceará, using techniques and criteria established in the literature, based on empirical and semi-empirical formulations. The delimited watershed had an area of 9.091 hectares, characterizing it as a small basin. For a 10,000-year return period, a design flow rate of 3.9406 m³/s was obtained associated with a rainfall intensity of 7.41 mm/min. Morphometric analysis indicated that the basin has a rounded shape, favoring the concentration of surface runoff and is, therefore, more prone to flooding, despite its good drainage. It is concluded that the hydrological study, combined with knowledge of local particularities, is fundamental for the efficient and safe reservoir sizing, considering the factors that directly influence its water supply capacity.