- Modeling Sanitary Wastewater or Foulwater with HYDRA Sewer Modeling Software -

Know
Your
Flows!

What wastewater flows go into the sewer system? Having a good method for calculating sanitary flows entering the sewer is a critical part of creating and maintaining a realistic model. Yet it is all too often treated as an afterthought. The powerful flow generation features in HYDRA® software make it easy for you to input, generate, and manage the flows for current and alternative scenarios.

Flexible Loading Options
HYDRA® software gives you great flexibility in ways to generate flows for the model. You can use any combination of a variety of methods. You can organize data on layers by land use characteristics, ownership parcel, or sanitary service areas (also called sewersheds or service basins). Or simply use a total daily volume associated with each pipe, as is common with other sewer modeling software. You can also use your own system for calculating flows (such as a spreadsheet or GIS application), and then bring the data into HYDRA® software.

HYDRA's Sanitary Flow Layers
HYDRA® software provides several graphical layer options for storing data to derive sanitary flows. Each type of sanitary flow can have its own individual diurnal pattern to time the flows throughout the day. The sanitary flow layers can use these factors:

Residential population characteristics (density, contribution per capita, percentage of population on septic systems)
Visiting population characteristics (density, contribution per capita, percentage of population on septic systems)
Commercial, industrial, or other types of sanitary flow (volume)

Sanitary Flow Diurnal Pattern

Sanitary Flow Layers

Sanitary flows generated from parcels

Realistic Distribution of Flows
HYDRA® software can perform polygon-polygon intersects for the purpose of distributing the proper amount of sanitary flow to each pipe in the collection system. Land use areas are intersected with the service basins to determine what portion of the total sanitary flow should be injected into each pipe in the collection system.

Alternative Scenarios
After you input the data for present-day population and are ready to try alternative future scenarios, HYDRA® software makes it easy to re-generate the sanitary flows. For example, to create a 5% population growth alternative, simply save the land use layer under a different name, such as "ALT_A". Then use the update query tools to multiply the population values by 1.05. Then regenerate the sanitary flows, and re-run hydraulic analysis - this time selecting the "ALT_A" sanitary flows - and view the results. That's all there is to it!

Peaking Factor Method Supported
HYDRA® software supports the traditional Peaking Factor Method, which is specified as the preferred method by many government agencies. If your project requires the use of the Peaking Factor Method, HYDRA® software is the model to use!

For indepth reading, check out Chapter 5 "Modeling Sanitary Wastewater" of the Hydra User's Manual.

FLASH