Data last updated 12/19/2025.
Note: Congaree and Wateree river inflows takes 3-5 days to reach Lake Marion.
The projected times of operation below are subject to change depending upon electrical system and lake management requirements.
Tentative Jefferies Hydro Discharge Times
| Date | Start Time | End Time |
|---|---|---|
| 12/19/2025 | 4 PM | Midnight |
| 12/20/2025 | 4 AM | 10 AM |
| 12/21/2025 | 2 AM | Midnight |
| 12/22/2025 | 6 PM | Midnight |
| 12/23/2025 | 4 AM | 10 PM |
| 12/24/2025 | 6 AM | 2 PM |
| 12/25/2025 | 6 AM | Midnight |
| 12/26/2025 | 4 AM | 10 PM |
| 12/27/2025 | 4 PM | Midnight |
| 12/28/2025 | Midnight | 10 PM |
Tentative St. Stephen Discharge Times
| Date | Start Time | End Time |
|---|---|---|
| 12/19/2025 | Not scheduled to run | Not scheduled to run |
| 12/20/2025 | Not scheduled to run | Not scheduled to run |
| 12/21/2025 | Not scheduled to run | Not scheduled to run |
| 12/22/2025 | Not scheduled to run | Not scheduled to run |
| 12/23/2025 | Not scheduled to run | Not scheduled to run |
| 12/24/2025 | Not scheduled to run | Not scheduled to run |
| 12/25/2025 | Not scheduled to run | Not scheduled to run |
| 12/26/2025 | Not scheduled to run | Not scheduled to run |
| 12/27/2025 | Not scheduled to run | Not scheduled to run |
| 12/28/2025 | Not scheduled to run | Not scheduled to run |
USGS Data Links
| Gauge Location | USGS Link |
|---|---|
| Jamestown (Santee River) | USGS 02171700 |
| Congaree at Columbia | USGS 02169500 |
| Santee at Ft. Motte | USGS 02169810 |
| Wateree at Camden | USGS 02148000 |
| Lake Marion at Elloree | USGS 02169921 |
| Lake Marion at Pineville | USGS 02171000 |
| Lake Moultrie at Rediversion | USGS 02171635 |
| Lake Moultrie at Pinopolis | USGS 02172000 |
| Discharge of SS (Santee River at St Stephen) | USGS 02171645 |
Lake Elevations
| Date | Lake Marion Elevation | Lake Moultrie Elevation | Rule Curve Elevation |
|---|---|---|---|
| 12/18/2025 | 74.66 | 74.58 | 73.67 |
| 12/17/2025 | 74.65 | 74.54 | 73.73 |
| 12/16/2025 | 74.74 | 74.44 | 73.79 |
| 12/15/2025 | 74.89 | 74.76 | 73.79 |
| 12/14/2025 | 75.01 | 74.98 | 73.85 |
| 12/13/2025 | 74.94 | 74.87 | 73.9 |
| 12/12/2025 | 74.92 | 74.82 | 73.95 |
| 12/11/2025 | 74.91 | 74.87 | 73.99 |
| 12/10/2025 | 74.86 | 74.77 | 74.02 |
| 12/9/2025 | 74.82 | 74.77 | 74.05 |
Daily Lake Discharges
| Date | Jefferies Hydro | St Stephen Hydro | Spillway Hydro | Spilling |
|---|---|---|---|---|
| 12/18/2025 | 4022 | 0 | 615 | 0 |
| 12/17/2025 | 3464 | 442 | 612 | 0 |
| 12/16/2025 | 4884 | 8247 | 610 | 0 |
| 12/15/2025 | 6569 | 9238 | 610 | 0 |
| 12/14/2025 | 4896 | 0 | 602 | 0 |
| 12/13/2025 | 2484 | 0 | 609 | 0 |
| 12/12/2025 | 4760 | 0 | 610 | 0 |
| 12/11/2025 | 3613 | 0 | 608 | 0 |
| 12/10/2025 | 3627 | 1 | 582 | 1 |
| 12/9/2025 | 5011 | 0 | 612 | 0 |
| 7-Day Average | 4333 | 1792.8 | 607 | 0.1 |
Upstream River Flows
| Date | Broad River @ Alston | Saluda River @ River Banks Zoo | Congaree Inflow @ Columbia | Wateree Inflow @ Camden |
|---|---|---|---|---|
| 12/18/2025 | 1760 | 921 | 3088 | 1713 |
| 12/17/2025 | 1957 | 918 | 2985 | 1917 |
| 12/16/2025 | 1806 | 912 | 2877 | 3125 |
| 12/15/2025 | 1850 | 910 | 3050 | 3118 |
| 12/14/2025 | 1936 | 913 | 3108 | 1520 |
| 12/13/2025 | 1960 | 907 | 3060 | 1613 |
| 12/12/2025 | 1924 | 884 | 3028 | 1991 |
| 12/11/2025 | 1881 | 1833 | 3956 | 2282 |
| 12/10/2025 | 2528 | 2417 | 5319 | 2504 |
| 12/9/2025 | 2415 | 2417 | 4915 | 2337 |
| 7-Day Average | - | - | - | - |
Estimated Lake Marion Inflows
| Date | Santee Cooper |
|---|---|
| 12/18/2025 | 5907 |
| 12/19/2025 | 6144 |
| 12/20/2025 | 5286 |
| 12/21/2025 | 4952 |
| 12/22/2025 | 5761 |
| 12/23/2025 | 6144 |
| 12/24/2025 | 6244 |
| 12/25/2025 | 5538 |
| 12/26/2025 | 4935 |
| 12/27/2025 | 4753 |
| 12/28/2025 | 5453 |