Basic water model use case (Water Overlay)

For all effective uses of any variant of the water overlay, you must first set up a basic water model. This water model includes both your hydrological system, as well as the parameters used to perform any calculations. The behavior of any water, whether it's pre-existing, expected inflow, or due to natural event or calamity, is affected by the presence of features which can capture or steer water in other directions. The more real-world hydrological features and hydrological constructions are loaded in, the more accurately the water flow can be simulated.

Requirements

Before getting started, there are a few requirements which must be met first.

Determine what overlay you need

The first step is to determine which variant of the Water Overlay best suits your needs. This depends largely on what primary calculation you wish to perform.

Create your project

The Water Overlay will be able to calculate most accurately if your project has been created with the following criteria in mind:

• Your project has been loaded in with a high-resolution DEM. This can be configured during the new project wizard.
• Your project is large enough to account for edge effects.

Prepare your data

The next step is preparing your data. Note that data can be skipped if you do not have this data, or the data is not applicable for your project.

The following data should be prepared. Click on any topic for more information.

Data	Description	Alternative/default
Water areas	Water areas set the water level of all open water in the area they envelop.	In the configuration wizard, it is possible to generate a single water area for the entire project area.
Weirs	Weirs allow for water to flow between bodies of water, with the amount of water increasing as the water level increases.	There are no default weirs in a project.
Culverts	Culverts allow for water to flow between bodies of water, with a maximum amount dictated by the size of the culvert.	For projects in the Netherlands some culverts may be loaded in as part of the project creation process.
Pumps	Pumps move water from locations with a lower water level to locations with a higher water level.	There are no default pumps in a project.
Inlets and outlets	Inlets are points where water can be added to the water system. Outlets are points where water can leave the water system.	There are no default inlets or outlets in a project.
Sewer areas	Sewer areas form controlled storage for water which ends up on constructions landing on sewer areas.	In the configuration wizard, it is possible to generate sewer areas based on the neighborhoods in the project area.
Sewer overflows	Sewer overflows are a way for water to flow out of the sewer, and back onto the surface water system.	There are no default sewer overflows in a project, even when sewers are loaded in or generated.

Steps

How to create a basic water model:

1. Add the overlay, as described here: How to add and remove an overlay.
2. Open the overlay's Water Overlay Wizard, and perform each step if possible. When in doubt on what to configure exactly, a step can be skipped.

Notes

The rainfall and groundwater variants of the Water Overlay already form basic water models when they are added to a project without further configuration.