Revista de Gestão de Água da América Latina (Water Management Journal in Latin America)

NATURAL AND ANTHROPIC EFFECTS ON THE QUALITATIVE ASPECTS OF WATER IN THE NIQUIM RIVER BASIN

Tue, 29 Apr 2025 00:00:00 -0300

The natural and anthropogenic effects on the water quality of the Niquim River, located in the São Miguel Hydrographic Region, were analyzed with the aim of developing a classification proposal. Qualitative water monitoring was carried out in the Niquim River Lagoon (RNL), the second near the city's water intake (RNC) and the third near the mouth (RNF). The results of the analyses were compared with the limits established by CONAMA Resolution No. 357/05. In the classification proposal, the basin was divided into 3 sections, for which classes 1 and 2 were suggested, but it was found that some parameters do not meet their predominant uses. In section 1, the aim is to increase DO and reduce BOD_5,20 and ammoniacal N, through the preservation of forest formations to reduce the organic load in this section. In section 2, it is necessary to reduce the BOD_5.20 and ammonia-N parameters by preserving vegetated areas, mainly riparian forests, to reduce the organic load in this section. In section 3, the BOD_5.20, ammonia-N, DO and E. coli parameters are above the levels established in the Resolution. In order to reach the limits of the proposed classification in all sections, it is necessary to correctly dispose of effluents, preserve green areas, and plan land use and occupation.

Changes in Water Color Related to Mining in Rivers of Southwestern Amazon Observed by Satellite

Tue, 29 Apr 2025 00:00:00 -0300

Given the importance of water resources, their monitoring is essential. Considering the size of Brazilian river basins, especially the Amazonian ones, the use of remote sensing tools becomes feasible, allowing for the monitoring of surface water quality, particularly color characteristics and total solids. The components present in the water alter its reflectance according to their characteristics, enabling the study and tracking of water quality. The main objective of this work was to identify changes in the water color of rivers in the Southwestern Amazon, within the sub-basins of the Ji-Paraná, Canumã, and Amaná rivers, mapping evidence of interactions and the impacts of mining and gold panning. This was achieved through reflectance angles and dominant wavelengths, understanding the formation of water color in the basins and the influence of mining and human activities. A statistical analysis of the average values of dominant wavelengths and suspended material data provided by ANA was conducted to verify whether the variations were significant between 1994 and 2021. Through statistical analyses, significant changes were demonstrated for higher average dominant wavelengths in most sections of the Ji-Paraná and Amaná basins, while for the Canumã River, the changes were mostly toward shorter wavelengths.

A MULTIOBJECTIVE AND MULTICRITERIA METHODOLOGY FOR SUPPORT TO THE PROCESS OF CONCESSION OF WATER USE RIGHTS

Tue, 29 Apr 2025 00:00:00 -0300

We proposed a methodology to assist in the granting of water use rights, using multi-objective and multi-criteria methods, and its application to the Preto River basin. We divided the basin into five zones, and we identified water demands and availability in them. We defined eight different development scenarios for the basin, taking into account aspects such as the location of irrigators in the basin, the type of irrigator, and their growth rate. From the interviews with experts, we established seven criteria, covering environmental, social, technical, and economic aspects. We evaluated these criteria using GIS and water balance using Acquanet. We applied three multi-objective methods (Compromise Programming - CP, PROMÉTHÉE-II, and TOPSIS) to four different sets of weights, defined by consulting experts and simulating “policies” to guide the granting process in the Preto River basin. The “policies” aimed to give priority to social, environmental, and economic aspects, in addition to a “neutral policy,” with all weights equal. The results for the different “policies”, after being normalized, produced an aggregated classification and established the concession scenario to be implemented in the basin. The methodology made it possible to define a water granting policy capable of considering conflicts and articulated with social policies.

MINEIRO WATER RESOURCES POLICY

João Paulo Rabelo, Carmino Hayashi (Author) — Tue, 29 Apr 2025 00:00:00 -0300

The management of Brazilian water resources is conducted through a system that possesses a holistic perspective on all aspects involving water management. Additionally, this system seeks to reconcile strategically important sectors of the country for the sake of water management. Minas Gerais is a state that plays a crucial role in the country when considering economic, social, and environmental aspects. Thus, understanding the water resources management system in Minas Gerais is fundamental for achieving cohesion in the management process at the national level. That said, this study evaluates the relationship between the water resources regulations in force at the aforementioned levels, traversing certain fields of water management in Minas Gerais and Brazil. It is evident that Minas Gerais plays a significant role in the management of water resources under its jurisdiction.

Use and occurrence of 2,4-D in Brazil: emphasis on drinking water quality

Tue, 29 Apr 2025 00:00:00 -0300

This study aims to provide a diagnosis of 2,4-D in Brazil, based on its environmental fate, sales, spatial distribution, and concentrations in raw and drinking water. An estimate of 2,4-D sales in Brazilian municipalities and states was conducted, considering data on planted area, sales, and authorized use in the country. The concentration of 2,4-D was analyzed through a systematic literature review and data processing from SISAGUA. It was found that 2,4-D shows a tendency for increased commercialization, with an annual average of 43,267 tons and an average usage rate per planted area of 0.65 kg/ha, with some notable regions. 2,4-D showed a high detection frequency, with values that, overall, did not exceed the maximum acceptable value (MAV) for drinking water in Brazil. It is concluded that 2,4-D is widely used and detected, however, this fact does not currently reflect a risk to human health through drinking water consumption.

Influence of seasonality on the characteristics and biological pre-treatment of landfill leachate

Tue, 29 Apr 2025 00:00:00 -0300

Factors such as climate, waste characteristics, age and operation of the landfill influence the flow and composition of landfill leachate, which must be monitored as they interfere with the treatment process. Although anaerobic and aerated lagoons are unable to bring the treated leachate into line with release standards, they function as pre-treatment and amortise its variability, preparing it for post-treatment. This study assessed the influence of seasonality on the flow, composition and biological pre-treatment of leachate generated in a landfill in a tropical region, by means of physico-chemical and flow analyses of the raw and pre-treated leachate. The influence of precipitation on the increase in flow and the variability of COD and BOD was confirmed5,20. Pre-treatment removed 60.8% and 36.6% of COD; 74.7% and 79.4% of BOD5.20, and 94.6% and 76.8% of N-NH4, respectively, in the dry and rainy seasons, but with remaining concentrations still high for direct use in post-treatment.

Challenges for effective implementation of urban drainage and stormwater management service fees in Brazil

Bruno Inocencio Henrique, Fernando Dornelles (Author) — Fri, 11 Jul 2025 00:00:00 -0300

Intense urbanization alters the water balance and impacts stormwater runoff, making Urban Stormwater Drainage and Management (USDM) services essential to mitigate the effects of heavy rainfall. This article analyzes the economic and financial situation of USDM services in Brazil based on data from the National Sanitation Information System (2015-2022) and addresses legal, institutional, and technical challenges for implementing an efficient charging system. A simplified financing model adaptable to various cities and regions is also proposed. The results show that of the 24 municipalities claiming to charge for USDM services, only one actually does. These services are mostly provided by direct public administration, with funding for maintenance, operation, and system expansion primarily coming from the general budget. While implementing charges could enhance service delivery, restructuring the institutions responsible for USDM is also necessary.

NEW PATHWAYS FOR SUSTAINABLE URBAN WATER MANAGEMENT

Fri, 11 Jul 2025 00:00:00 -0300

Accelerated urbanization and climate change intensify the challenges of sustainable urban water management, particularly in emerging and low-income economies. In these regions, recent unplanned urbanization and insufficient or inadequate infrastructure increase population vulnerability to extreme events. The concept of sustainable urban water management has historically evolved under various terminologies—BMP, LID, SUDS, WSUD, Green Infrastructure, and Sponge Cities—reflecting different priorities and cultural contexts. Recently, it has been framed under the new term Nature-Based Solutions (NBS). Urban water management encompasses seven essential components: drainage, detention, retention, infiltration, evaporation, treatment, and reuse. Incorporating as many of these components as possible into stormwater systems ensures sustainable urban water management, fostering resilience and adaptation in cities facing climate change challenges. Additionally, integrating gray infrastructure with technological components and natural elements is a crucial step toward achieving sustainability in these systems, while also providing essential ecosystem services. This study presents a conceptual review of sustainable urban water management, outlining its components, requirements, and steps for implementation. It emphasizes the importance of multidisciplinary approaches and strong community involvement in these initiatives. Furthermore, it highlights the need to strengthen regulatory and financial frameworks to encourage the adoption of the necessary measures for achieving sustainable urban water management.

Control of surface runoff at different scales in an urban community through event-based and continuous simulations

Altair Maciel de Barros, Marllus Gustavo Ferreira Passos das Neves (Author) — Fri, 11 Jul 2025 00:00:00 -0300

Green and blue infrastructures integrate ecosystem-based measures into urban planning to mimic the natural water cycle, controlling runoff at its source and reducing peak flows. However, their implementation in consolidated urban communities can face challenges due to limited space and socioeconomic constraints, which hinder installation and maintenance. In this context, this study evaluated the performance of runoff control devices in the Grota do Cigano sub-basin (SBGC), an urban community in Maceió-AL, using SWMM to calibrate a hydrological-hydraulic model for the current scenario, which has a critical overflow point at its outlet, and simulating four intervention scenarios. In scenarios I and II, detention microrreservoirs (MRD) were simulated in residential lots, while in scenarios III and IV, detention reservoirs (RD) were simulated near the outlet. In scenarios I and III, the devices were sized based on the drainage channel capacity, whereas in scenarios II and IV, they were designed according to pre-urbanization flow rates. The RD proved to be more viable, effectively controlling runoff across the entire SBGC while occupying less space. Additionally, devices designed based on drainage channel capacity were more practical, balancing flow control efficiency with minimal space usage.

Origin and background of the barium anomaly in the groundwater of the Barreiro’s Alkaline-Carbonatite Complex – Araxá – MG

Tiago Antônio Torres Gomes, Ana Elisa Silva de Abreu (Author) — Fri, 11 Jul 2025 00:00:00 -0300

The anomalous values of barium in the groundwater of the Barreiro’s Carbonatite Alkaline Complex (BACC), located in the municipality of Araxá, in the Alto Paranaíba Igneous Province, have been studied since the early 1980s, when this element was detected dissolved in groundwater at high concentrations. The objective of this work is to investigate the possible origins and what levels can be considered natural for barium in the CACB. The methodology used was based on the statistical analysis of monitoring well data to determine the background, as well as geochemical solubility analyses, SEM, and XRD in clay soils to estimate the origin of barium, in addition to the statistical treatment of barium concentrations in soil samples collected XXX. The results of the XRD analyses of the lateritic covers did not detect barium minerals, despite the chemical and solubility analyses showing significant levels of the element. The geochemical solubility analyses of barium from the clays of the lateritic covers show values that can reach 16 mg/L. This condition indicates that barium is probably in the form of free ions (Ba2+), adsorbed on clay minerals and iron oxide-hydroxides, which constitute the capping materials of the alkaline dome, being mobilized from recharge and transported to the saturated zone. The statistical analysis of the results of barium concentrations in groundwater shows that the value of 5.52 mg/L can be adopted as a reference applicable to the background levels of barium in the groundwater of the CACB. The use of groundwater from the interior of the dome should be evaluated with caution for human consumption and recreation, as the maximum permitted values of 0.7 and 1.0 mg/L, respectively, are lower than the defined background value.

PROGRAMA NOVO PINHEIROS. AVANÇAMOS RUMO A REVITALIZAÇÃO DOS RIOS URBANOS BRASILEIROS?

Fri, 11 Jul 2025 00:00:00 -0300

As climate change intensifies the frequency and severity of extreme events, the revitalization of urban rivers and the creation of green and blue infrastructure through Nature-Based Solutions (NBS) emerge as a significant opportunity for city adaptation and the construction of more sustainable, resilient, and livable cities for future generations. The rapid urbanization process of the São Paulo Metropolitan Region has resulted in the degradation of its watercourses and the distancing of the population from the water element, which reflected in the current state of its main rivers. The emergence of the "Tietê Program" in the 1990s represents a milestone in the beginning of concern for the recovery of the Tietê River and the movement to achieve this purpose, culminating in various other actions such as the "Novo Pinheiros Program", the subject of the present article. This study aimed to analyze the "Novo Pinheiros Program", an initiative of the Government of the State of São Paulo to recover and revitalize the Pinheiros River. For this purpose, a qualitative analysis of the actions carried out by the program was conducted, as well as an assessment matrix of the actions and their effectiveness in the purpose of recovering and revitalizing the Pinheiros River. Additionally, a comparative analysis of the program's actions with 10 other similar programs was conducted. Thus, the study provides an answer to the central question: "Are we progressing towards the revitalization of Brazilian urban rivers?".