|FISHERMEN EDUCATED ABOUT WATER QUALITY|
|November 25, 2000 12:00 am|
Water quality monitoring and assessment may sound boring, but watershed monitor Cindy Myers showed the South Coast Fishermen last week that it is anything but a dry subject.
Many of the fishermen listening to Myers presentation were already familiar with the tree-planting efforts of watershed councils in Curry County.
What they didnt know was what a complex science riparian shade restoration is, or how it is measured and monitored.
It turned out that fishermen who thought watershed councils just planted trees haphazardly to shade streams didnt know the half of it.
The watershed councils received grants for water quality management, especially for high temperature rivers, those with average highs of more than 64 degrees.
The councils have used those grants to monitor shade, sediment, and other water quality issues on the Chetco, Pistol, Elk and Sixes rivers, along with Euchre and Floras creeks.
Myers said theyve seen a temperature reduction in one stream already.
She showed the fishermen how watershed monitors studied lower Floras Creek, which suffers from a lack of vegetation as it runs through pastures.
Incoming solar rays are projected in a model. The streams temperature is a balance between incoming solar radiation and water flow. The rays are measured with a solar pathfinder, which is essentially a dome set on a stand in the stream. On Aug. 1, the most solar radiation, and the least shade, is usually recorded between 11 a.m. and 1 p.m.
Shade is also affected by the width of the stream. Channels that are too wide have little shade, even with redwood trees on their banks.
Myers showed the fishermen maps where lengths of streams in the county were marked in different colors to show the percentage of existing shade on them.
Other maps showed the potential shade increase along the streams. Tree planting projects could increase the shade on Floras Creek by 20-32 percent.
The years needed to get that increase are also estimated. Floras Creek may need 38-57 years to achieve that percentage of increase in shade.
Myers said water temperature monitoring shows that streams dont cool down quickly when they flow through shaded sections. Shade is needed on the upper sections to keep rivers cool.
Water temperature monitoring involves site objectives, continuous recording thermometers, streamflow measurements, temperature profiles, and the occasional temperature-measuring blitz like last summers Chetco Checkup.
The checkup showed that the tributaries of the Chetco River cool the hot main stem.
So that solar radiation doesnt affect the readings, thermometers are placed in shaded spots deeper than 12-18 inches.
Temperature data from 1995 to 2000 showed that temperature layers in streams are not uniform from bank to bank.
Temperature strata bend upward in the middle of channels. Groundwater entering streams also changes temperatures.
The hours and days that rivers have readings above set points like 64 or 70 degrees are also recorded.
The data showed 1998 to be one of the warmer years for Curry County rivers, and 1999 to be one of the cooler years.
If any of the South Coast Fishermen still thought monitoring was just a case of sticking a thermometer in a river, Myers explained how the effect of sediment and streamflow on temperature is measured.
Channel depth and substrate must be measured, because solar radiation can radiate back up from the bottom.
Channel width-to-depth ratios are measured downstream from confluence and upstream from constrictions like gorges and bridges.
Sediment can destabilize channels and change the sinuosity of the river.
Streamflow affects temperature too. The maximum temperatures are recorded in times of declining flow.
The cumulative effects of solar exposure must be factored in, as well as evaporation from ponds, dams and irrigation, and the exchange between the surface and subsurface.
Water quality parameters must also be monitored. Rivers are rated by season in the water quality index.
The Winchuck is excellent year round. The Chetco is good in the summer, but poor the rest of the year. Sediment has caused listings for streams in Northern California.
Myers will submit a grant to get a bigger water-quality program going.
Her presentation showed that the grant money is producing more work and data than most people were aware of.