Holistic Approach to Watershed Management and Freshwater Conservation and Rehabilitation: A Case Study

Rebeca González Villela, Javier J. Sánchez Chávez, Luis A. Bravo Inclán, Marco Mijangos C., Jorge Izurieta, A.

Cecilia Tomasini O., Pedro Rivera Ruíz, Gabriela Mantilla Morales, and Alfonso G. Banderas Tarabay

Instituto Mexicano de Tecnología del Agua, México

Abstract: A Multidisciplinary methodology that describes for the watershed of Laguna de Tuxpan the climate, topography, geology, soil, vegetation and land use through GIS. The topography (maximum altitude of 1731 m). The bathymetry(capacity of 18.89 Mm3, an area of 4.1 Mm2 and a maximum depth of 7.86 m). The physicochemical and environmental parameters, show the generation of 107.01 kg of nitrogen per year (22.93% by point sources and 77.07% by diffuse sources). Tomatal river produces 18.7 t of sediment on the regions of average sloping, this equates to a lost of 7.45 t ha-1 on average throughout the basin. The water quality is within the maximum permissible limits for the development of aquatic life. The lake is classified as warm water body, shallow and tropical, with a holomíctic blend, or a water body mesotrophic — eutrophic, through plankton community. The pollution and toxicity by Vibrio fischeri, Daphnia magna, Selenastrumcapricornutum and Microcistinawas not present in the lake. The presence of six types of phthalates, plus the incidence of herbicide atrazine in the lake, point out as source of pollution to the trash of the area and agricultural activity. There are contamination by the presence of fecal coliform and total suspended solids of human and natural origin in the watershed. Is proposed a strategic plan of recuperation: 1) a program of promotion and adoption of conservation practices for hillside land, 2) construction of little dams within channels for the control sediment and runoff infiltration to help the recharge the aquifer, 3) the river corridor recovery through of reforestation, 4) management of less polluting agrochemicals, 5) relocation of human settlements of the river corridor, 6) rechanneling of the river, 7) control of invasive species management of the corridor and the lake, and 8) management of the water urban residuals through social participation.

Key words: ecosystemic analysis, limnology