Vladimir,

Yes, Minimum Volume is the minimum volume when the tank is at its minimum level. Minimum volume is an optional field that is generally only defined when the Minimum level is unknown. Be aware though that any minimum level defined will cause the percent full calculations to use the minimum level as 0% full, so take care of using that field if you are comparing to percent full values based on 0% full being the bottom of the tank. Many people often leave the minimum level for a tank at zero to avoid any confusion and just know that certain tank values are not reasonable. As long as you know how the model considers a minimum level, you are ok, but be aware of how it can impact the model runs and percent full calculations.

From the Help file:

**Cylindrical Tank**

A cylindrical tank represents any tank that has a constant

diameter in relation to its high and low water levels.

Specify the Tank Type as Cylindrical in the Type field of the

Model Explorer - Attribute Tab window.

A tank needs the following fields to be populated:

__Elevation__ -The elevation (above sea

level) of the bottom of the tank, ft (m).

__Minimum __

Level - The lowest allowable water level above the bottom of the tank

(ex. 3 ft.), ft (m)

__Maximum Level__ *-*

The highest allowable water level above the bottom of the tank (ex. 22 ft.), ft

(m).

__Initial Level__ - The height of water

above the bottom of the tank (ex. 12 ft.) when the simulation is to begin, ft

(m).__Diameter__ - The diameter of the tank, ft (m).

__Minimum Volume__ - Only required when minimum level is not

known, ft3 (m3).

**Note:** Minimum Volume is an optional field

and needs to be entered only in cases when the Minimum Level is not known but

the Minimum Volume is known. Also for Cylindrical tanks the curve field needs to

be left blank.

Please let us know if you have any further questions.

Patrick Moore