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ON THE Russian RIVER: Oh, no! It’s Low-Flow…. again!

by Don McEnhill

GROSS! – Low flow in the River, with a concentration of runoff nutrients our yard loves (such as nitrogen and phosphorous), is heaven for algae.

Russian River

Here we go, it’s deja-vu all over again this summer with another low year for Lake Mendocino in Ukiah making an impact on flow levels in the Russian River. Our office has been taking calls from River users since the first week of June when the River flows were substantially below mandated minimum flows of 125 cubic feet per second at USGS Flow Gauge near Hacienda Bridge in Forestville.

After those calls on low-flows, we started getting calls about a massive algae bloom below the Monte Rio Bridge on the lower River. The locals told us they had never seen such a major bloom even in the lower water years such as last year and 2004. Those prior years’ lower flows resulted in impacts to boaters but less impacts to water quality.

Lower flows negatively affect water quality by increasing water temperatures and concentrating pollutants like nitrogen and phosphorous, which are nutrients that plants in our yards need to grow. One of the common responses to these conditions is algae blooms. Algae likes warm and nutrient rich water, and lowered flows on the Russian create these conditions. Algae blooms can trigger human reactions from annoyance to disgust.

Of course, when I was a kid, our reaction was to heave those hunks of the green slimey stuff at our sisters! The desired reaction was predictable, screaming horror. If fish could scream, they would when confronted by massive algae blooms. When water quality favors plant growth – such as an algae bloom – it is devastating to aquatic life like salmon or steelhead juveniles.

Algae, being a plant, produces oxygen in the water by day. However, at night, plants consume oxygen, competing with fish that need oxygen to breathe. So when we have major algae blooms, we have major crashes in oxygen levels just before sunrise, when the sun starts off a new day of photosynthesis and plants again create oxygen.

If you were a juvenile steelhead, this is like being strangled each morning by the lowered oxygen levels, and even if it doesn’t kill you, it can weaken you enough to make you easy prey for a smallmouth bass or pike minnow. Makes getting hit by an algae toss not so gross, doesn’t it? What can we do about algae blooms and lack of flows?

Algae bloom Solving the “more water in the River” part is up to our community; homeowners, businesses, farmers and government all using less water, which leads to less taken out of the River! On nutrient reduction we can all play a part as well: making sure pet waste is cleaned up – especially when at the River! – not using too much fertilizer on landscaping, and preventing sediment or dirt from getting in the River all reduce nutrient loading.

We can all benefit from more water and less nutrients in our River, whether we’re a fish or a sister.