Once again Balancing the Basin called on its old sage to make a prediction on the summer conditions at the Corps’ Savannah River reservoirs. His editors told him to keep it serious this year.
Writing the 2016 version of this post proved easy enough. Heavy, heavy rains near the end of 2015 and into the beginning of 2016 caused tremendous runoff into the reservoirs that lasted several weeks. This runoff filled the reservoirs to overflowing (literally) which gave ample reserves for the summer recreation season.
Now, 12 months later, the conditions have not repeated. Most of 2016 was dry (see last week’s post) which eventually drained the surpluses from the beginning of the year despite three reductions in outflows.
By starting the year in drought level 2 we need substantial rainfall to catch up. It could happen and has happened – like in 2009. The reservoirs started December 2008 barely above level 4 but by Memorial Day 2009 the reservoirs were in normal conditions and by Thanksgiving reached flood stage.
Also from December 2012 to June 2013 the reservoirs shot from level 3 to flood stage. However, such a dramatic rise this year would be another anomaly, albeit a very welcome one.
The good news: This year has already started well which is typical for January through March or so. This means the reservoirs can start to recover if the winter rains continue, or if the upper basin receives (dare I say it?) some snow.
Snowfall melts into the ground, not directly benefiting the reservoirs, but the saturated ground allows more runoff in subsequent rains. Still, with nature’s recent cycle of drought-rain-drought-rain, most forecasters see a continuation of drought in 2017.
This doesn’t mean a dire season. In keeping with the drought management plan, Savannah District water managers refrain from increasing outflows until reservoir level rise two feet above the drought trigger level.
This gives the reservoirs additional time and resources to recover. It also gives the water managers the flexibility to keep the reservoirs balanced ensuring users throughout the upper basin benefit from the rainfall regardless of which reservoir actually receives the rain.
If history gives us a glimpse into the near future, reservoir levels should rise in the next three months then hold mostly steady for the beginning of the summer. Again, historical data indicates low rain for the summer. Drought forecasters, with much more education than I have, predict more drought, even over the next several weeks.
Finally, having grown up on a west Texas cotton farm with no irrigation, I learned to hold out hope for rain, even when forecasters predicted none. Those hope-filled habits are hard to break.
I do know this: Whether refreshing rain or parching Texas sun, my family survived and thrived and found a way to make a joyful life regardless of what we were given. Likewise, we know the drought cycle here will end and the reservoirs will return to normal levels.
— Billy Birdwell, Corporate Communications Office