Thursday, August 19, 2010

Beaver Creek Water Quality: What Is That Green In The Water?

Update; picture taken of Beaver Creek from South Beaver Creek Rd. bridge on August 24, 2010. The green bloom is back in the creek.  Something is going on with Beaver Creek water quality and it changes quickly.

The other day while kayaking on lower Beaver Creek, I noticed that the water was bright green and turbid in several reaches of the creek.  This particular color is familiar to me from seeing algal blooms in lakes.  A few days later the green was gone and the creek had returned to its normal summer color and clarity.  In the summer when creek flow is low, the possibility for algal blooms in the lower creek is increased.  The creek water has a longer residence time, allowing algae to concentrate and form blooms.  Sunlight increases and water temperature can warm.  Then algae can bloom as they are not washed out into the ocean.  Is this algal bloom harmful for fish and their food?  It depends.  If the bloom leads to lowered oxygen in the water, especially during night time, then fish kills can occur.  Otherwise, the bloom may supply needed food for feeding fish and their prey.  There are no simple answers.  We look for obvious signs, such as fish kills to determine harm, but sublethal effects such as stressed fish are also possible.  These stress effects are more difficult to see.
So I looked at data sources to see if Beaver Creek has been identified as having water quality problems.  The Oregon Department of Environmental Quality (DEQ) keeps a database for problem waterways.  Problem waterways are defined under 303(d) listing as having abnormal and harmful levels of any of these factors: sediment; bacteria; temperature; dissolved oxygen; nutrients; weeds or algae; chlorophyll a; pH; and toxins.  Once a waterway is 303(d) listed, it may be subject to formulation of Total Maximum Daily Load (TMDL) analysis and management to remediate problems.
Beaver Creek is not 303(d) listed by DEQ.  Recent monitoring (2006-2008) by the Lincoln Soil and Water Conservation District (LSWCD) often showed, especially in the summer, that bacteria were elevated and oxygen, oxygen saturation, and pH were decreased to 303(d) water quality violation levels.  We do not know historical patterns of Beaver Creek water quality, so baseline comparisons are not possible.  These data are warning signs that Beaver Creek water quality could be improved before larger problems develop.
Historically (past 100 years) the creek and watershed have been influenced by fires, wildlife, and humans through forestry, livestock and crop farming, septic systems, fishing, road building, and recreation.  The creek produces healthy runs of coho, cutthroat trout, and steelhead.  Beaver Creek appears to be a robust system that has large potential to heal itself from the effects of natural and human-induced perturbations.  Clearly, the past pioneers and present residents of the Beaver Creek watershed have been good stewards of their lands and there is room for improvement, as indicated by 303(d) water quality criteria.  The strength of the Beaver Creek watershed suggests that improvement measures will result in positive results.  
Suggestions for improvement of fish spawning habitat, especially in forested areas, have been outlined in a watershed analysis by the Siuslaw National Forest.  Steps for improvement of farmed areas have been outlined in a report by LSWCD entitled Mid Coast Agricultural Water Quality Management Area Plan.  Changes in forestry and agricultural practices to improve water quality are based on voluntary and cooperative efforts, with the financial aid of grants.  The management plans make suggestions and landowners, government and private, may follow them according to their motivation and ability, in an effort to adhere to water quality guidelines.
How can Beaver Creek water quality be improved and who is responsible?  Following the LSWCD management plan we see five sub-sections for potential concern.  These include: near-stream management areas; nutrients and bacteria; fine sediment; irrigation water management; and pesticides.  Prevention and management of pollution from agricultural and forestry activities in the Mid Coast Agricultural Water Quality Management Area is administered by the Oregon Department of Agriculture through Oregon Administrative Rules (OAR) 603-095-2200, 2220, 2224, 2240, and 2260. The land owners are responsible for their own activities and not responsible for the activities of other land owners, conditions that exceed 25 year, 24 hour storm events (flooding), or other exceptional circumstances.  Site-specific conditions are important for improvement measures and the owner’s knowledge and judgement is of primary importance.  Access to waterways by livestock is allowed for steam crossings and watering as long as riparian vegetation is maintained.  Owners are not responsible for the effects of wildlife on riparian vegetation.  Examples of recent management actions in Lincoln County are given in this report.
The LSWCD management plan recognizes several common-sense activities for waterway improvement.  Consult the plan for detailsPrevention and Control includes voluntary measures to keep waterways within the the bounds of 303(d) water quality criteria.  Riparian Areas and Streams includes fencing, off-stream livestock watering, rotational grazing, livestock exclusion, planting riparian vegetation, and in-stream structures.  Nutrient and Manure Management includes controlled field manure applications, manure storage in covered and contained areas away from streams, limit livestock access to saturated soils, cover heavy traffic areas with sand or rock, and site barns and slaughter areas away from streams to isolate and manage leachate.  Erosion and Sediment Control includes livestock rotation to maintain vegetation, control of runoff by diversion, maintain riparian vegetation, and plant cover crops in fields.  Management of Pesticides includes follow label instructions, use more integrated pest management, insure containment of mixing and spilling of pesticides and petroleum products.

Next time you are out on a waterway, take a moment to appreciate all of the hard effort, common sense, and responsibility that farmers, foresters, fishers, and recreation makers posses in their efforts to make a living, feed people, and conserve valuable ecosystems that support all of us.  When an ecosystem is degraded, our responsibility is to support positive repair efforts and return to a healthy state of wildness in collaboration with farmers, foresters, and fishers.  Together, we make good neighbors, strong communities, and healthy economies.  

Posted by michael

1 comment:

0s0-Pa said...

At first I was going to say "Algae", but now I know there is something else involved that would turn it that shade of green. Time for some sediment control management!