## Overview:

*Reservoirs* are open bodies of water that store flow and are connected to
nodes by means of an energy-based equation. Reservoirs are considered instantly
well-mixed. The Reservoirs Table specifies the identity and physical properties of the reservoir.
Connections to nodes are specified in the Reservoir Connections table.

## Tables:

### RESERVOIR

The RESERVOIR table defines the name and physical properties of the reservoir.

#### Field Descriptions

- NAME
- Name of the reservoir. This is the identifier of the reservoir used in other tables.
- AREA
- Surface area (million sq ft) of the reservoir at typical depth. This area is used to calculate volume changes.
- BOT_ELEV
- Elevation (ft) of the bottom of the reservoir.

#### Table Info

- Identifier:
- NAME
- Include Block:
- GRID

### RESERVOIR_CONNECTION

This table lists reservoir connections to neighboring nodes. Flow through reservoir connections
is calculated using the following formula

$$Q = C_{to} sqrt[ 2g(z_{node} - z_{res}) ] ... z_{res} < z_{node}

Q = C_{from} sqrt[ 2g(z_{res} - z_{node}) ] ... z_{res} > z_{node}

Where:

- C
_{to} and C_{from} are coefficients representing
the hydraulic efficiency of the reservoir
connection and the nominal Area perpendicular to flow.
- g is gravity and
- z
_{res} and z_{node} are the water surface elevations at the reservoir and node (node surface is assessed by means of a reference channel that has no reservoirs attached to it).

#### Field Descriptions

- RES_NAME
- Name of reservoir at which connection is specified.
- NODE
- Number identifying the node at which connection is specified.
- COEF_IN
- Coefficient from node to reservoir, greater than zero. If you compare the reservoir equation to
the gate or other orifice equation you will find that the reservoir coefficient actually
folds several quantities into one parameter: a flow efficiency (between zero and one) and a area of flow.
If you have an observation of the area normal to flow, the coefficient should be some fraction of this aperture.
- COEF_OUT
- flow direction out of the reservoir.

#### Table Info

- Identifier:
- RES_NAME, NODE
- Parent Table:
- RESERVOIR
- Parent Identifier:
- RES_NAME
- Include Block:
- GRID

## Usage Notes:

- A node may not have more than three reservoir connections and must have
at least one ungated channel connection.