Engineering Study for Construction of Sediment Trap and Sediment Basin in the Siahdarvishan and Chomseqal Rivers through Engineering, Procurement and Construction Project

About Project

10 rivers meet the Anzali Wetland; each of them releases different concentrations of contaminants and sediment into the wetland and consequently led to remarkable water quality loss. Among these 10 rivers, Chomesqal and Siahdarvishan Rivers discharge a large amount of contaminated sediment. Asarab Consulting Engineers Co. conducted a comprehensive study, to estimate the sediment volume, its concentration and deposition rate from the rivers. According to the result of this preliminary study, volume and dimension of sediment trap was calculated for trapping inlet sediment. Then the water quality in the wetland would be enhanced considerably and also the habitat of wading birds will be rehabilitated and conserved properly. Besides the above mentioned advantages of this program, it will prevent wetland to be dried.

Actual services:

This project included two sections, the main section was sediment trap and basin designing and the other one was Environmental Impact Assessment of sediment trap and basin construction, in order to meet the main objectives of the project, the following services have been accomplished:

• Physiographical, meteorological, hydrological, and geological studies
• Sedimentological Studies
• Identification of borrow pit resources in the spatial scope of the project
• Socioeconomic status assessment in the affected area
• Exploring the current land-uses
• Morphological study of the mentioned rivers
• Hydraulic study of sediment transportation from the river to the wetland
• Designing the sediment trap based on sediment transportation
• Investigating environmental status of the wetland and limnological studies
• CCHE2D simulation for choosing the best alternative

Environmental Impact Study of sediment trap construction in construction and operational phase:

• Estimating contaminant levels carried by inlet sediment from Chomesqal and Siahdarvishan Rivers
• Identification and assessment of environmental impacts caused by sediment basin construction considering alternatives of implementation, non- implementation and implementation with environmental mitigating measures
• Adverse impact assessment of operations on fishing activities
• Investigating environmental impacts noise pollution, air pollution, soil degradation, interference in the aquatic environment and visual pollution
• Investigation on probable accidents and incidents during construction and operation
• Provision of Environmental Management Plan for the sediment trap and basin construction and operation

The sediment trap is able to detain 350,000 M3sediment of the two rivers during 2 years.