Appendix F: Lift Station Calculations
SSD River Bend Creek Lift Station
Hydraulic Calculations
| Pump Calulcations | Figure |
|---|---|
| Surface Elevation @ Lift Station (Source – Topo) | 5695 feet |
| Pump “Off” Elevation | 5675 feet |
| Elevation @ High Point (Source – Topo) | 5711 feet |
| Depth of Force Main @ High Point | 8 feet |
| Length of Pipe (ft) | 1400 feet |
| Internal Pipe Diameter (in) | 4 inches (4″ HDPE DR 11 (200 psi) Basis of Design) |
| Peak Flow Rate (gpm) | 120 gpm |
| Type of Pipe | Polyethylene |
| Hazen-Williams Coefficient | 140 |
| Scour Velocity (ft/sec) | 3.06 ft/s |
| Velocity Head | 0.146 feet |
| # of 90 deg elbows | 12 |
| # of 45 deg elbows | 2 |
| # of other minor elbows | 4 |
| # of isolation valves | 6 |
| # of check valves | 2 |
| Entrance Loss Coeff. | 0.5 |
| Static Head | 28 feet |
| Friction Head | 12.9 feet |
| Minor Losses | 1.8 feet |
| TDH = | 42.64 feet |
Meets SSD maximum scour velocity of 6.0 ft/sec and minimum CDPHE scour velocity of 2.5 ft/sec
| Emergency Storage Volume | Figure |
|---|---|
| Maximum Month Average Daily Flow | 42174 gallons per day |
| Maximum 8-hr flow Ratio of Daily Flow | 43.1% %, per SSD hydrograph |
| Minimum Storage Volume – Design | 18177 gallons |
| CDPHE Requirement: 8-hrs average daily flow | 14058 gallons |