Sewerage Networks

Sewerage Network Design

A sewer network is an infrastructure that fundamentally comprises pipes and manholes, and is characterized by a network layout and a hydraulic design.

The layout of a sewer network defines the flow direction within the network following a tree-like structure where all manholes are connected to the outfall through a unique path. Given a layout, a hydraulic design establishes the diameter for each pipe and the inverted elevation of its two endpoints. The main purpose of sewer network plan is to obtain a minimum-cost design capable of transporting a specific flow rate for each pipe, while satisfying all hydraulic and operational constraints to comply with local regulations. To achieve this, POD has developed an exclusive software called “NetU” with robust engine design to provide the designers with special features to deliver an optimized plan. To learn more about NetU click here.

Design of sewerage network comprises main items as follows:

➣ Analysis of Design flow for each conduit

• Determine the design period
• Demographic analysis to project and forecast population in the design period
• Regional Analysis to specify land-use, population density, city or rural service boundary and extensions
• Per capita flow analysis for residential users and commercial or other nonresidential effluents
• Infiltration and inflow analysis and storm runoff estimation

➣ Assessment of existing network

• Preparing the layout of existing sewerage network
• Evaluation of construction data as pipe diameter, pipe slope, upstream and downstream invert elevation.
• Modeling the existing network to determine the capacity with the latest flow analysis during the design period
• Attune the qualified existing network with new proposed sewerage network; the connection and any modification if needed.

➣ Define design criteria;

• Pipe and conduit material
• Manhole material
• Min. Pipe size
• Conduit velocity range
• Conduit depth of flow range
• Conduit slope range
• Conduit construction depth range
• Modeling and design method

➣ Hydraulic Design

• Preparing the layout of sewerage network in the area; drawing a tree-line network within a city or a vast area is a time-consuming operation. POD has developed an outstanding feature to draw the network in an automatic process of an aerial image of the plan area
• Creating the network model by allocating topographical and flow data for each element
• Designing the network to specify the conduit size and invert elevation and considering design criteria and constraints.

➣ Design of other structures of sewer network including;

• Manhole
• Drop manholes
• Inverted siphon
• Overflow structures
• Weir structures

➣ Construction Plan and drawings

• Drawings are so important how to transfer the design data of sewerage network in the construction process in the simplest but precise way. The construction drawing by this concept will guarantee the quality of construction, and also leads to decrease in the construction period. POD delivers this service by fully-automated software to create construction drawings in plan and profile sheets both facilitating implementation of a detailed plan of sewerage network. POD network plan and profile maker provide some exclusive features as in the following:
  • Precise data illustration of pipe and manhole
  • Best direction and place to avoid interference of data
  • Add or remove any data from the collection
  • Customizing the drawing method for example in a table or by a leader line
  • Changing the font type and size easily
  • Select and filter the elements by specific data field
  • Open, save, edit and copy the drawing in CAD-based platform