understanding your remarkable riparian area
TRANSCRIPT
Understanding Your Remarkable Riparian Area
Catching the water
Storing the water in the land
An Overlooked Opportunity
Some function and some not
Which side of this creek would you like to own?
A
B
Myths About Creeks and Rivers
1. Floods are bad2. Droughts are bad3. Streams should be wide
and straight4. Large wood clogs creeks
and should be removed5. Removal of riparian
vegetation increases stream flow
6. Cut-banks are bad7. People have to fix them
What is a Riparian Area?
Soil Water Vegetation
Soil
Water Vegetation
Gears of a finely tuned machine
Soil Wat
erVegetation
ID Values
What are the values you appreciate about healthy creeks and riparian areas?
Different People have different values
Clean WaterReliable Supply of Water Abundant Livestock ForageFish and Aquatic HabitatWildlife HabitatNatural Beauty/Recreation
Some recognized values
How and why does a creek operate and function the way it
does?
What is a Properly Functioning Riparian Area?
Properly Functioning Riparian Area
• Dissipate stream energy
• Stabilize banks• Reduce erosion• Trap sediment• Build / enlarge
floodplain• Store water • Floodwater retention • Groundwater recharge• Sustain baseflow
• Water quality• Water quantity• Forage• Aquatic habitat• Wildlife habitat• Recreational
value• Aesthetic
beauty
Adequate vegetation, landform or large woody material to:
Physical Function
Values
Soil
Water Vegetation
Soil and Water
Energy
Channels Collect Raindrops
Base Flow
Bankfull Flow
1 – 2 Year Flood
Channels come in all degrees of crooked
Crooked river
Walla Walla River, 1964
Why Rivers Bend
Active Floodplain
High velocity water
Low velocity water
Floodplains Dissipate Energy and Trap Sediment
Floodplain
Water Table
Flooding Recharges Water Tables
Excessive Energy (Erosion) Enlarges the Channel
Lane’s Relationship, 1950 without vegetation
Enlarged channel
Down-cutting Drains the Water Table
Bankfull flow well below floodplain
Down-cutting: Loose Access to Floodplain
Loss of floodplain
Water Table
Riparian Sponge
Rock Layer
Where does flow come from during dry times?
Headwater Stream
The Water Table Sustains Base Flow
Riparian Sponge
Loss of sponge in headwater streams means reduced base flows
Overly Wide Channels Reduce Sediment Transport Ability
Sediment can not be efficiently transport
Natural Channel Restoration
Degraded and eroded channels can be restored
Dissipating Energy and Catching Sediment
Function will return at a new elevation.
Recovery can start with one plant!
Riparian Sponge
Vegetation is the Key to Healthy /
Functional Creeks and Riparian Areas
Lane’s Balance Buffered by Vegetation
Dissipate EnergyReduce ErosionTrap SedimentHelp Create / Enlarge Riparian Sponge
Slow Down the Water
The Role of Riparian Vegetation:
Burro Creek1981
Burro Creek2000
Bear Creek, Oregon Aug 1977Bear Creek, Oregon Aug 1977
Bear Creek 1977
Bear Creek 1996
Riparian Recovery
1976 to1994
Colonizers
Stabilizers
A Strong Riparian Plant Community is Essential
Flooding is Essentialif the plants are there
20072008
2011
Drought is Essential
Woody Plants are Essential in many streams
Little walnut Gravel bar StabilizerFAC; SR: 6 / 7
Vigor of Woody Plants
Dead Wood is Essential
Vegetation tells the Riparian Story
How to Protect and Manage Riparian Areas:
• Creeks / Riparian Areas are special places; they deserve preferential treatment
• Remove the hindrances that inhibit natural restoration
Hindrances to Healthy / Functional Riparian Areas:
• Farming too close to the bank• Mowing, spraying close to the creek• Manicured or highly altered landscapes next to
the creek• Grazing concentrations in creek areas• Excessive deer, exotics, hogs in creek areas• Burning in riparian area• Removal of large dead wood• Artificial manipulation of banks / sediment• Excessive vehicle traffic in creek area• Low water dams• Poorly designed road crossings / bridges• Excessive recreational foot traffic in creek area• Excessive alluvial pumping or other withdrawals• Excessive populations or monocultures of invasive
plants
Its really about people
