English to Spanish Tech/Engineering Mining & Minerals / Gems almacén de roca estéril

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The design of the underdrain system was completed for the final extent of the WRSF. The design flow of the secondary collectors of the underdrain system was determined as follows;
1. The area within the final footprint of the WRSF that drains towards each secondary drain was estimated based on the 1-metre contour existing conditions topographic information;
2. The volume of infiltration was estimated for each secondary drain by multiplying the design precipitation event by the reporting area considering an infiltration coefficient of 0.4; and
3. The design flow was calculated by dividing the infiltration volume by the design criteria drain time.


no entiendo bien la última línea espero que puedan ayudarme es muy urgente gracias