Posted April 6, 2008
Several recent rainfalls have finally made a significant dent in the low water level at Falls Lake (see the 180-day graph ending Thursday April 3rd), and during the late afternoon to early evening on Saturday it finally happened. As of about 6:00 pm yesterday Falls Lake rose to it's guide curve, or "normal" level of 251.5 feet above mean sea level, meaning the "conservation pool" of the lake is 100% full. Depending on rainfall and streamflow patterns over the coming weeks and months, this may or may not hold up, but is certainly good news in the short term. Over the course of the weekend, the level rose from 251.1 feet at 6 am Saturday to 251.5 feet at 6 pm Saturday and was up to 251.9 feet by Sunday morning. I was unable to find a handy reference to see when the lake was last at or above the normal elevation, but the graph attached to this post shows it was around 7 feet or more below normal six months ago, with a strong upward trend in the wake of late winter/early spring rains.
To this point, inflow to the lake has spiked and waned rapidly with variations in streamflow following rain events. In order to become a little steadier we'll have to see groundwater levels recover more fully, which will depend on the frequency and intensity of rainfall ahead. Unfortunately, there is no good way to make a confident projection for now as to whether we can expect rains to run above normal, near normal or below through the coming months, as long-term climatalogical indicators (see map for April-May-June above) are currently judged by the Climate Prediction Center to provide about an equal chance of those three outcomes.