what is in your creek - clackmas watershed 2008

8/9/2019 What is in Your Creek - Clackmas Watershed 2008

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Portland State University Capstone Clackamas River Basin Council Student Watershed Research Project

Day in Damascus

On July 26th, 2008, Portland State University students andmembers of the Clackamas River Basin Council spent the

day at the Day in Damascus festival playing games with

the kids and educating them about the macro-

invertebrates found in the creeks of the Clackamas

watershed. However, it wasnt all fun and games. A dozen

other PSU students spent the day in the field, collecting

water samples and important data from Rock, Richardson,

and Eagle creeks and streams. In 2008, land owner

participation increased by 12 sites from 2007.

NutrientsThe primary measures of nutrient loading, phosphates

and nitrates, are associated with many non-point

pollution sources, such as livestock waste, failing septic

systems and fertilizers. Excess nutrients can artificially

stimulate plant growth, resulting in algal blooms which

impacts water quality. Nitrate levels in unpolluted water

bodies should generally be below 1.0 mg/l. Phosphates in

unpolluted water bodies should generally be below 0.1

mg/l.

Fertilizer Effects

Nitrogen and phosphorus are the two main componentsin fertilizers. The numbers found on the packaging of

most chemical fertilizers (such as 20-20-20) are the

nitrogen-phosphorus-potassium components. Most plants

require 14 times more nitrogen than phosphorus. By this

comparison, most fertilizers provide far more phosphorus

than plants require relative to nitrogen provided. The

relative increase of phosphorus and decrease of nitrate in

a stream may be due to algae that use the nitrate leaving

an excess of phosphorus. As watersheds become more

urbanized, we often notice a trend of increased

phosphorous.

Map modified for print. May not include all sample locations.

Whats in Your Creek?Snapshot Event Monitoring Results: Clackamas Watershed 2008

Site Code Reference:

CLE- Clear Creek DCR- Deep Creek (1)

EGL- Eagle Creek (2,3) RCK- Rock Creek (9-11)

RCH-Richardson Creek (7,8) UNK- Unknown Tributary

NFC and NFD-North Fork Deep Creek (4-6)


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VegetationRiparian vegetation is plant life that grows along the

stream and sometimes extends roots directly into the

water. These plants provide shade, habitat, and bank

stability to the stream. Invasive species are non-native

plants that compete for nutrients and sunlight with native

species. Within the watershed there are a number of

invasive plants that many of us are familiar with such as

Himalayan blackberry, knotweed, and English ivy.

TemperatureThe temperature of the water in your creek or stream is

very important to the overall health of the aquatic

ecosystem. Stream water that is warmer than the

standard of 17.8C (64F) is considered unsuitable for

salmonid spawning. Increased temperature reduces the

dissolved oxygen concentration, making it difficult for fish

to breathe. Wastewater inputs, water from ponds, and a

lack of riparian vegetation for shade can increase water

temperature. Waters warmer than 25

C (77

F) are lethalto salmon and trout. Two sites met or exceeded the

standard temperature limit, Deep Creek and the North

Fork of Deep Creek. These sites were also the last two

sampled and time of day could influence temperature.

Dissolved OxygenDissolved oxygen is required for the growth and

development of aquatic life. Algal blooms, high

temperatures, and decomposition of organic matter can

cause dissolved oxygen to drop to levels harmful to

aquatic life. The optimal level for salmon is 9.0 mg/l. A

level of 8.0 mg/l is the DEQ standard for fish bearing

streams. Levels below 3.5 mg/l are likely fatal to salmon.

A level below 3.0 mg/l is stressful to most vertebrates and

other forms of aquatic life. Two sites are below the

optimal levels: Eagle Creek and the North Fork of Deep

Creek.

TurbidityTurbidity is a measure of how clear the water is.

Suspended solids (including total dissolved solids) in

water can reduce the transmission of light either through

absorption or by scattering. High turbidity can have anegative impact on submerged aquatic vegetation,

bottom dwelling organisms and the ability of juvenile

salmon to catch prey. Since salmon rely greatly on their

visual abilities, the lower the turbidity the better. Salmon

will avoid water with high silt loads where visibility is


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extremely low. Thus, high turbidity can impact salmon

migration. Oregon DEQ is in the process of developing its

own state standard, but the Washington state standard is

5 NTU. Turbidity spikes are seen for the majority of sites,

with the highest being at Eagle, North Fork of Deep Creek,

and Richardson Creek.

PhosphorousPhosphorous is an element that is required by all living

things. Excess phosphorous in freshwater promotes rapid

growth of algae which can lower dissolved oxygen levels.

Phosphorous sources include detergent, fertilizers,

industrial waste, pesticides, and the decomposition of

organic matter. The EPA recommends less than 0.10 mg/l

phosphorous for lakes and streams. This item was

exceeded across the board, with the worst levels being in

Rock and Deep Creeks.

NitrateNitrate is the most common form of nitrogen found in

streams. Excess nitrate in streams can cause algal bloomsand be detrimental to aquatic life. The surface water

standard for nitrate is not more than 10 mg/l nitrogen. All

of the locations sampled were well below the standard.

Nitrate does not appear to be a significant water quality

issues at these sites.

AmmoniaAmmonia is a form of nitrogen which is usually

transformed into nitrate when oxygen is present. High

concentrations of ammonia can reduce oxygen levels and

be toxic to aquatic life. Common ammonia sources are

sewage and decomposing organic matter. While there

are no Oregon standards for ammonia, the optimal

concentration in surface water is less than 0.05 mg/l

Nitrogen. Ammonia spikes, associated with local land

uses, will require more investigation to pinpoint their

sources.

pHpH is the measure of the acidity (low) or alkalinity (high)

of a solution. A pH reading of 6.5 to 8.5 is acceptable for

most fresh water invertebrates and fish. Algal blooms,

sulfur compounds, and nitrogen oxides released fromcombustion engines, and industrial waste can change the

pH. The results show that this is not a significant water

quality issue in the Clackamas River Basin.


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Summary:Findings from this years analysis show high phosphorus

at nearly all locations. This could indicate overuse of

fertilizers within the watershed. A further investigation

would be beneficial to better understand the source of

the elevated levels in these streams and creeks.

Temperature continues to be a concern within the

watershed. We are within the range of suitable salmonhabitat. However, we found that the temperatures of

most streams are warmer than optimal. Spawning salmon

are very sensitive to temperature which is also directly

related to dissolved oxygen. Also, water temperature is

the easiest thing to change by increasing or encouraging

native riparian vegetation to shade the stream. These

plants may be available from the Clackamas Watershed

Council at no cost for qualified landowners.

Tests on other nutrients and pH fall generally within

natural ranges, indicating overall healthy streams and

creeks within the watershed.

Why a healthy watershed is important:

Healthy streams for fish, wildlife and people Rock, Richardson, Eagle, Clear Creeks flow into the

Clackamas River, upstream of your drinking water intake

Salmon spawn and rear in the lower portions of the

creeks and will continue to do so if water quality is

preserved

Easy steps to help maintain a healthy watershed:

Keep septic tanks maintained Remove invasive plants, such as Japanese knotweed

and plant native vegetation along the creeks to keep the

waters shaded and cool

Dont put yard debris, garbage or chemicals in or around

the creeks

Reduce or eliminate the use of chemicals, pesticides

weed-killers and fertilizers. Instead, use compost or mulch

to fertilize

For more information and ways that you can help improve

water quality in your watershed contact:

[email protected] or call (503)558-0550

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Portland State University Capstone Clackamas River Basin Council Student Watershed ResearchProject

what is in your creek - clackmas watershed 2008

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