Calculate Pond/Pit Volume

This command is a customized and simplified method for calculating volumes in a situation in which the entire volume to be calculated is below the perimeter elevation, such as in the case of a pond or pit. The complimentary command, Calculate Stockpile Volume, is for the opposite situation, in which the entire volume to be calculated is above the elevation of the perimeter. 

The program internally computes BASE and FINAL grid surfaces from drawing geometry. The base surface is calculated from a 3D polyline representing the perimeter of the area being analyzed. If that 3D polyline is drawn on the PERIMETER layer, the command will automatically detect and use it. If no 3D polyline is found on that layer, you have an opportunity to manually select the 3D polyline to use. The 3D polyline perimeter can be drawn with the Draw 3D Polyline Perimeter command before using this routine.

The 3D polyline perimeter is also used as the inclusion perimeter for the volume calculation.

Additional 3D polylines can also be specified to more precisely define the BASE surface.  These must be on the BASE_BREAKLINE layer to be used for this purpose. These can be generated by the Draw 3DPoly Base Breakline routine. 

The FINAL surface is calculated from all of the other selected drawing entities such as points, line, inserts, and polylines, along with the perimeter polyline, but not including the BASE_BREAKLINE polylines. These features are used only in computing the BASE surface.

You have the option of setting the resolution of the grids.

Besides reporting the entire volume between the two surfaces, the report also includes the volumes at an elevation interval from the bottom to the top. These stage-storage volumes can also be stored to a capacity file (.cap) that can be used with the Hydrology module. In addition to the stage-storage volumes, the Report Incremental Volumes option reports the storage within an elevation range instead of relative to the surface.

The Make 3D Grid File and Two Grid Surface Volumes commands, used in combination, are an alternative to this command, and in any situation in which there are both cut and fill volumes between the surfaces, that combination must be used to generate accurate results.

Prompts

Ignore Zero Elevations [<Yes>/No]? press Enter
Select Pond/Pit entities and perimeter.
Select objects: pick the objects that define the surface and the 3D polyline perimeter
Select Pond/Pit perimeter polyline: pick the polyline

Make Grid File dialog Set the resolution and then click OK.
Sample Volume Report:
Lower left grid corner : 8361.29,10856.76
Upper right grid corner: 8940.96,11302.31
X grid resolution: 50, Y grid resolution: 50
X grid cell size : 11.59, Y grid cell size: 8.91

Pond/Pit volume : 602,182.5 C.F., 22,303.06 C.Y., 13.82 Acre-Ft
Area: 114,312.7 S.F., 2.624 Acres
Elevation Range: 987.08 to 1000.00

Storage Volumes
Elevation    Storage(AcreFt)  (C.Y.)    (C.F.)     Area(Acre)
990.00       0.26121          421.4     11378.5    0.281
992.00       1.18631          1913.9    51675.9    0.646
994.00       2.85639          4608.3    124424.4   1.033
996.00       5.46346          8814.4    237988.4   1.591
998.00       9.13982          14745.6   398130.8   2.083
1000.00      13.82421         22303.1   602182.5   2.624

Increment         Storage(AcreFt)  (C.Y.)    (C.F.)     Area(Acre)
990.00-992.00     0.92510          1492.5    40297.4    0.365
992.00-994.00     1.67008          2694.4    72748.5    0.387
994.00-996.00     2.60707          4206.1    113564.0   0.558
996.00-998.00     3.67636          5931.2    160142.4   0.492
998.00-1000.00    4.68438          7557.5    204051.7   0.541

Pulldown Menu Location: Surface >> Stockpile/Pond/Pit Volumes
Keyboard Command: pitvol
Prerequisite: Data representing the pond/pit surface and a 3D polyline representing the perimeter of the pond/pit.