William H. Harsha Lake water level history
Daily records since 2002 · Level today: 730.61 ft
Highest on record
777.10 ft
May 4, 2011
Lowest on record
723.23 ft
Dec 1, 2008
Today
730.61 ft
Oct 21, 2026
Years of data
25
since 2002
In short
Across 23 complete years, 2007 had the lowest average level (729.96 ft) and 2011 the highest (734.87 ft).
On average the lake is lowest in November (729.69 ft) and highest in May (734.81 ft).
William H. Harsha Lake level, all years
Loading chart…
Measured
Normal range for the date (middle 50% of past years)
Full pool
Lowest years
Years ranked by their lowest daily level.
- 2008
- 2011
- 2012
- 2007
- 2004
Yearly highs and lows
| Year | Average | Low | Low date | High | High date |
|---|---|---|---|---|---|
| 2026 (294 days) | 732.47 | 728.92 | Feb 9 | 746.07 | Mar 7 |
| 2025 | 733.40 | 728.86 | Dec 3 | 763.20 | Apr 9 |
| 2024 | 730.87 | 728.80 | Nov 9 | 740.06 | May 9 |
| 2023 | 731.54 | 728.96 | Mar 16 | 741.79 | Mar 26 |
| 2022 | 732.33 | 728.89 | Mar 14 | 749.40 | Feb 26 |
| 2021 | 732.04 | 728.90 | Dec 9 | 745.04 | Mar 5 |
| 2020 | 732.24 | 728.94 | Mar 30 | 748.73 | May 20 |
| 2019 | 734.42 | 728.58 | Oct 26 | 758.74 | Feb 16 |
| 2018 | 733.98 | 729.09 | Nov 29 | 763.84 | Mar 2 |
| 2017 | 732.01 | 729.01 | Jan 16 | 747.10 | Mar 2 |
| 2016 | 731.63 | 728.92 | Jan 13 | 739.61 | Jan 1 |
| 2015 | 732.80 | 728.91 | Jan 29 | 752.63 | Mar 17 |
| 2014 | 731.41 | 728.86 | Jan 16 | 741.93 | Feb 22 |
| 2013 | 731.51 | 728.96 | Mar 4 | 740.06 | Dec 23 |
| 2012 | 730.96 | 724.41 | Apr 13 | 739.75 | May 3 |
| 2011 | 734.87 | 724.04 | Mar 28 | 777.10 | May 4 |
| 2010 | 730.82 | 726.74 | Mar 10 | 741.46 | May 3 |
| 2009 | 731.93 | 726.58 | Jan 4 | 742.06 | Aug 5 |
| 2008 | 731.74 | 723.23 | Dec 1 | 752.88 | Mar 22 |
| 2007 | 729.96 | 724.80 | Oct 22 | 744.35 | Jan 16 |
| 2006 | 731.93 | 729.05 | Feb 2 | 742.22 | Mar 14 |
| 2005 | 734.68 | 729.04 | Feb 27 | 771.83 | Jan 18 |
| 2004 | 732.35 | 724.90 | Jan 23 | 752.97 | Jan 10 |
| 2003 | 732.29 | 729.04 | Jan 15 | 747.35 | May 12 |
| 2002 (322 days) | 732.04 | 728.97 | Mar 1 | 746.82 | May 9 |
Levels in feet. Partial years show the number of days with data.
Monthly averages
| Month | Average | Lowest | Highest |
|---|---|---|---|
| January | 731.37 | 724.90 | 771.83 |
| February | 731.72 | 723.77 | 761.79 |
| March | 732.66 | 724.04 | 763.84 |
| April | 733.32 | 724.10 | 767.72 |
| May | 734.81 | 729.73 | 777.10 |
| June | 733.73 | 730.41 | 754.16 |
| July | 733.12 | 729.44 | 740.71 |
| August | 732.83 | 727.49 | 742.25 |
| September | 732.12 | 725.75 | 749.34 |
| October | 730.61 | 724.60 | 738.41 |
| November | 729.69 | 723.24 | 738.01 |
| December | 730.12 | 723.23 | 746.00 |
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Daily levels as CSV (8,784 rows; credit the original agencies listed below)