Although this happens every year, it is still poorly understood among many folks. According to the City of Akron, which uses this body of water for its water supply, it seems to be all about keeping the water moving to prevent stagnation and nutrient loading that leads to algal blooms. Read on for a more detailed explanation circa 2013.
-Dan Best, Naturalist
East Branch is shallow, and nutrient-rich because of the neighboring communities around it. But that makes the regular draining of the reservoir really noticeable at certain times of year. Because it’s so shallow and the shoreline is such a shallow grade, losing an inch of water looks like a foot of water.
We drain East Branch relatively low because we need to keep the water flowing; if we let the lake stay stagnant, the water blooms green. We also need to keep the river flowing, and even just a little bit of release does that.
We do algal testing at least once a month, and in the summer two to three times a month or weekly, depending on the numbers. We grab samples and count them, then send them to a lab to have toxins detected. Those results definitely affect how much water we decide needs to come out of the reservoir. The lower the algal counts, the less water; the higher the algal counts, the more water to keep the water moving.
We also do what we can to keep the water from being too old, and do water quality monitoring. We almost always have something coming out of East Branch because we don’t want to impair the river downstream.
So ultimately we release between 5 and 20 million gallons a day, and I’d say normally 15 million gallons a day. On average we release about 10 million gallons in the fall, and when it’s dryer, just because we don’t want to empty the lake but we’ve got to keep the water moving. So there’s always a seasonal dip in the fall.
When we get that first melt, the first really big snow melt surge, or during crazy rain events, we have it open more to try to move that water before it’s flooding. The dam is old, so we don’t want to have a ton of water behind the dam.
We don’t really use it so much for water supply, but more for storage and supplemental water. Water takes two days to get to Akron.
-Jessica Glowczewski, City of Akron Watershed Superintendent