Watershed System

Physical Properties

Stream flow(cfs)

Stream Channel Pattern

Substrate

Chemical Properties

pH

Dissolved Oxygen

Temperature

Nutrients

Turbidity

Biological PropertiesRiparian Zones

Macroinvertebrates

Water Testing Project for the North Fork River

Water testing day is FridayMay 11th at the North Arm Trailhead.

Physical Properties of a Watershed System

Stream Flow Stream Shape

Stream Flow

The amount of water that flows past a specific point in a

stream over a period of time.

Natural Influences that affect Stream Flow

• Climate • Season• Watershed• Meandering• Substrate• Groundwater• Vegetation

Human influences affecting stream flowDamsChannelization Land use

Why do we care about Stream Flow?• Water quality : affects turbidity (sediment load) and dissolved oxygen

• Aquatic life : creates different habitats for fish and bugs

•Vegetation: needs overbank flooding for nutrients

•Flooding: controlled for human structures

•Water storage: determines how and when water should be stored

Method to measure & calculate stream flow

1. Measure a 10 m section and mark it with rocks.2. Throw a stick in above this section and use a stop

watch to measure the time it takes the stick to travel the 10 m section 3 separate times. Average the times.

3. Divide the average time (sec) by the distance (10m) to get the velocity (m/s).

4. Measure the depth (m) & width(m) to find an area (m2).5. Stream flow = velocity (m/sec) x area (m2)

What influences stream shape?

Substrate Type

Stream Channel Pattern

Riffle/ Run /Pool Ratio

Substrate Types

Silt Sand Cobble

Gravel Boulders Bedrock

Method for Recording observations of substrate

1. Step into the stream, without looking bend down and pick up some sediment.

2. Tell your partner the type of substrate you are holding, have them record the type with a tally mark.

3. Take 50 samples in and along the river section. 4. Tally your total number of observations for each type

of substrate.5. Multiply the number of observations of each type by

2. This will equal the % out of 100 for each substrate.

Top View of Stream

Stream Channel PatternsCross-section view

meandering

straight

braided

Meandering Stream

Found invalley bottomswithout much slope. Slower Velocity.

Mixture ofsand bars& suspendedsilt particles.

Big pools, some riffles and runs

Straight Stream

Steep gradient, fast flowingSubstrate is predominantly cobble and gravelMostly runs some riffles

Braided Stream

River continually splitsand rejoins. River moves across broad flatplains. Slow and fast velocities.

Mixture of silt,Sand, and gravel.

Mostly runs andriffles.

Habitat areas of a Stream Channel

Run

run

Run

Riffles have high oxygen amounts essential for macroinvertabrates (bugs) and spawning fish.

Runs where fish feed and travel

Pools where fish hide and rest from the current

Method for Recording Riffle Run Pool Ratios

1. Take one step next to your river section, look across the river.

2. Record a tally mark on your sheet that shows if you see a riffle, run, or pool

3. Make 50 observations.4. Total the tally for each characteristic.5. Multiply the totals by 2 to find the % riffle,

run or pool that your river section contains.

Natural Influences affecting Stream Shape

• Friction created by substrate

• Velocity

• Vegetation

Human Influences affecting Stream ShapeDevelopment, logging, mining, grazing can destroy vegetation which causes more water and sediment to drain directly into a stream rather than being filter through groundwater.

Channel alterations, ie. straightening of a stream along a highway or through a city center

Dams prevent downstream flooding but then stream nutrients are not distributed throughout the floodplain to plants.

Why do we care about stream shape?Stream shape affects water quality

Straightening of a stream increases velocity, which results in higher erosion rates and more turbidityDarker streams impact temperature and amount of sunlight that reaches plant life.

Stream shape affects habitat.A straight stream does not have the variety of habitats found in a meandering stream

Stream shape impacts flooding

How will you interpret your results?Physical Characteristics of the river will be correlated to the

chemical and biological parameters.

Some Examples:Channel pattern and shape will effect velocity and erosion

which will in turn effect temperature and oxygen and/or nutrients.

Substrate will be related to velocity and oxygen which will determine how many bugs are in the river.

Riffle/Run/Pool ratio will indicate the diversity of the aquatic habitats and in relation to this the diversity of life in the stream. High diversity correlates to high water quality.