Water Quality Monitoring

Copel periodically monitors the quality of the water in its reservoirs, assessing the limnological conditions in the area of ​​influence of the hydroelectric generation projects, with a view to ensuring legal compliance and multiple uses of the waters.

In general terms, the monitoring of water quality in reservoirs is mainly guided by two Resolutions: 

  • ANA-ANEEL Resolution No. 03/2010: establishes that the person responsible for the concession must carry out four monitoring campaigns a year in at least one point in reservoirs with an area greater than 3 km².
  • CONAMA Resolution No. 357/2005: legislation that establishes the reference standards of water quality to be met in rivers and reservoirs, according to each classification class.

Copel has water quality monitoring stations at all its plants, and the number of stations varies according to the characteristics of the reservoir, such as area, time of residence and history of water quality. Currently, the monitoring network has 41 monitoring stations in 18 generation projects, 18 of which are classified as river stations (upstream or downstream of the reservoirs) and 23 stations in the body of the reservoir.

Table 1 – Number and typology of stations and associated developments:

APC – Apucaraninha2 Reservoir
CAS/CAV – Cavernous Complex1 River / 2 Reservoir
CHE – Chimney1 River / 2 Reservoir
CIM – Chopim1 Reservoir
GNB/DRJ – Secret/Jordão Derivation2 River / 3 Reservoir
GJC – Mauá2 River / 3 Reservoir
GBM – Foz do Areia2 River / 3 Reservoir
GJR – Caxias2 River / 2 Reservoir
GNA – Guaricana1 Reservoir
GPS – Capivari/Cachoeira3 River / 1 Reservoir
MBI – Marumbi1 Reservoir
PGI/SJR – Pitangui/São Jorge2 River / 2 Reservoir
FRA – Figueira2 Rio
MEL – Melissa1 Reservoir
VAU – Salto do Vau1 Reservoir


It should be noted that the parameters analyzed in river stations differ from the parameters analyzed in reservoirs. Reservoir stations have a particularity: collections are usually carried out at two depths, determined based on the IQAR methodology. When anoxia occurs (absence of dissolved oxygen), collection is performed at one more depth. The table below shows the parameters analyzed at the river stations, and at each of the depths of the reservoirs:


Table 2 – Monitored parameters – QdA – river and reservoir:


River samples 

Samples in

reservoir (Prof. I) 

Samples in

reservoir (Prof. II*) 

Samples in

reservoir (Prof. III*) 







Total phosphorus


Total phosphorusTotal phosphorusTotal phosphorus




Total number


Total numberTotal numberTotal number







Total Ammonia Nitrogen


Total Ammonia NitrogenTotal Ammonia NitrogenTotal Ammonia Nitrogen

Total inorganic N


Total inorganic NTotal inorganic NTotal inorganic N
PotassiumPotassiumTotal SolidsTotal Solids

Cell count (cel/mL) and identification

of phytoplankton




Total Solids


Total Solids
Settling SolidsSettling Solids

Total Coliforms


Total Coliforms


Thermotolerant ColiformsThermotolerant Coliforms









Oils and Greases




Cell count (cel/mL) and identification

of phytoplankton


* Depths II and III refer to the depths defined in the IQAR methodology

Monitoring results are expressed through three indices¹:

  • IQA – Water Quality Index
  • TFI – Trophic State Index
  • IQAR – Reservoir Water Quality Index  

All monitoring data feed the Water Quality Management System – QdA, software developed to provide Copel’s water quality management. The results are presented to the environmental agency through annual reports.


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