7 minute read
PROBLEMATICS
PROBLEMATICS- PART II
I.
Advertisement
II.
III.
“The different physical modifications made to the system, the increase in the discharge of wastewater and the introduction of organic matter and chemical substances, have gradually been decreasing the environmental quality of the fluvial system.” (Pérez-Munguía and Pineda-López, 2005)
II. III.
RIVER’S ACTUAL SITUATION
In order to understand the river’s situation, it is important to first understand what happens beyond the river’s bed. Entering the urban fabric, parallel to the river in the urban zone there is an important industrial area. The Balvanera industrial park (in purple), dumps its chemical waste into the river, without any monitoring.
Similarly, there is an important section of the river where the presence of mixed housing units is observed. How does this affect the river?
Since law implementation is weak, Pueblito’s drainage is discharged directly into the river, bypassing treatment plants that ironically sit idle. Next, Northwest of the river, in the rural area of rainfed and irrigated agriculture, waste from the municipal slaughterhouse is dumped, and this same contaminated water is taken by farmers (illegally) to irrigate crops.
It becomes a cyclic problem.
PROBLEMATICS- URBAN SCALE
It can be observed at the city scale level, where the problems occur in the river. In the less developed areas, there are irregular settlements, which are illegal in all of Mexico, since there should no construction 30 meters to the sides of the riverbed. In these areas there are drainage and municipal slaughterhouse dumps; some without any type of sanitation. Another problem occurs in the center of Pueblito, where the slopes of the river were rectified with masonry walls.
SST
Corresponds to total suspended solids. They are surface waters with strong impact of water discharges raw residuals with high load pollutant.
TOXICIDAD
Toxicity in source waters of landfills and industries.
DQO
Chemical oxygen demand. It is a method used to measure the amount of industry’s waste in the water.
DBO
It is the biochemical demand for oxygen. The higher the BOD, less oxygen is available for aquatic life forms.
E-COLI
Surface waters with strong bacteriological contamination. It is an indicator of contamination that indicates human, animal or water fecal untreated waste.
COLI-FEC
Surface waters with strong bacteriological contamination.
RIVER CONTAMINANTS
Taking into account the urban/rural context, and the current uses of the land, it is possible to understand how is it that Río el Pueblito is contaminated.
CONAGUA is the public organism that carries out annual monitoring of the 42 bodies of water in the state of Querétaro. 32 of the 42 are currently at red light, as can be observed in the graph. Río el Pueblito is one of the 42.
To carry out the classification, 7 indices are taken into account: TSS (total suspended solids), toxicity, COD (chemical oxygen demand), BOD, (biochemical oxygen demand), E-COLI and COLI-FEC (fecal coliforms). ).
Río el Pueblito has indices that exceed the permissible values, placing it at the red light.
Without underestimating the sanitation attempts, the river, given its context, reverses the same sanitation and therefore its traffic light becomes understandable.
AQUIFEROUS VALLEYS
An aquiferous valley is a natural formation of rock or sediment that stores and conducts groundwater, which is accessed through wells and springs. The National Water Law contemplates that CONAGUA must publish in the Official Gazette of the Federation the availability of national waters by aquifer. To do this, the Official Mexican Standard makes calculations to establish the recharge, volume, demand of the ecosystems and the volume of extraction thereof.
The aquifer Valle de Querétaro has an extension of 484 km2 and partially covers the municipalities of Querétaro, Corregidora and El Marqués. However, the use of the aquifer has been closed since 1957.
On the other hand, the Valle de Huimilpan aquifer has an extension of 211 km2, and covers part of the municipality of Corregidora, Huimilpan and Pedro Escobedo. This aquifer also has closed seasons for its use since 1957.
The sources of both aquiferous valleys are Río el Pueblito and Río Querétaro.
PRESA EL BATÁN
Adjoines with the urban sprawl problematic and the waste from industries, drainage, the trail, and agriculture, what happened to that river where people could go and swim in it?
Why is it now considered a sewage canal and not a river?
1990
Some important precedents for the current situation of the Pueblito River is the construction of the El Batán Dam in 1990.
CONAGUA and the government of the state of Querétaro made the construction of the Batán dam possible; initially with the idea of supplying 187 hectares and providing drinking water to 25,000 inhabitants of the municipality of Corregidora.
The dam has a capacity of 6,500,000 m3, and stores the waters of the Huimilpan, El Pueblito, Bravo, Hondo rivers, the Taponas stream and waters from the San Francisco springs. According to senior citizens who knew the river before the dam was built, they affirm that “the river
always carried water.”
What are the repercussions of the construction of the dam?
The hydrological regime is altered by the presence of the dam, which has caused the natural loss of the flow of the flows. This means that there is less water available and a higher risk of flooding, since water is only released in large rain
events.
What happens to the river when there is no water? In the photo, it can be seen what happens under the Constituyentes bridge. In the absence of water this scenario is repeated at different points along the El Pueblito river. Who owns all this land without water? People begin to negatively appropriate the river, a clear example is this photo. This space becomes “no man’s land”.
INVASIVE SPECIES
Native species have been severely affected by invasive species. These were brought in by outsiders, and released into the river. The Casquito turtle, the Crayfish and the canyon Crab are threatened by the Carpa, Mojarra, white Capri, Cara Cara, Sunfish and Largemouth Bass.
ONGOING STRATEGIES SINCE 2011
As aforementioned, strategies have been implemented along the river since 2011. These are found on the map to the left. One of the most important strategies is the use of Bio-Enzym. It is a biological catalyst that breaks down organic matter. It is discharged into the river once a week at two important points along the river: after the private area, and in river’s section where wastewater and the municipal slaughterhouse discharges its waste. The efforts to decontaminate the river are useless if they act in isolation.
NEW PROPOSAL
The new proposals arise based on the previous ones and after having observed the degradation and alteration of the river. The intention is to close the ditches, which initially provided drinking water to the inhabitants of Pueblito, but today they only divert the water from the river and direct it to the municipal drainage. The next strategy is to regenerate the entire riverbed through a careful selection of endemic vegetation. On this same scale, it is intended to make the river a national park, in order to ensure its total regeneration and that it is monitored by the national guard.
