Overview of Exercise Module 1 – Geologic Setting Module 2 – Flow Regimes Module 3 – Downstream Effects

Module 1 – Geologic Setting Goals – Based on topography and geology, delineate reaches and dams that are likely to have similar downstream issues.

Module 1 – Geologic Setting Data Overview Reach Map Topographic Map Geologic Map Longitudinal Profiles Table Of Dam Information Historic Event Chronology

What Did You Learn? What Characteristics Did You Base Your Reach Delineation On? Are These Likely To Be The Same For Another River? Based On Where Each Dam Is Located, Do You Expect Them To Affect The River Downstream In Similar Ways? Which Reservoirs Are Likely To Have The Greatest Rates Of Sediment Accumulation?

Module 1 Summary The Geologic Setting And Geomorphic History Of Each Dam is Unique. Therefore Dam Effects Must Be Evaluated And Viewed Within The Larger Geologic Context.

Module 2 – Flow Regimes Goals – Determine how dams have affected the flow regime of the Clackamas River.

Module 2 – Flow Regimes Data Overview Plumbing Schematic / USGS Site List Discharge Peak Flow Flow Duration Oak Grove Hydrographs

What Did You Learn? Do All The Dam-Imposed Changes In Flow Regime Result In Geomorphic Change? How Different Is The Predicted Geomorphic Change Below Each Of The Dams?

Module 2 Summary Within The Same Basin, Some Dams Do Not Significantly Alter Flow Regimes, While Others May Result In Measurable Hydrologic Changes. Such Changes May Have Different Geomorphic Consequences Downstream.

Module 3 – Downstream Effects Goals Synthesize geologic, hydrologic, and topographic information to generate likely key issues and recommend studies to resolve those issues.

Module 3 – Downstream Effects Data Overview Reservoir Sediment Data North Fork / Faraday Data Harriet Data River Mill Data Identification of Studies Determining Importance Allocation of Funding

By Using Aerial Photos and Sediment Trap Data: (Previous Slides) Identify Downstream Effects From Each Dam Predict Likely Channel Changes Record Observations

By Using Aerial Photos and Sediment Trap Data: Determine The Relative Importance of Each Study Determine Where to Allocate Funding

What Did You Learn? Is It Important To Evaluate All Possible Effects? Will Every Group Involved Rank The Potential Effects The Same?

Module 3 Summary Downstream effects and related impacts of dams are related to dam type, operating rules, and geomorphic / geologic settings. Understanding the relative importance of each effect allows appropriate studies and research goals to be identified. Downstream effects and related impacts of dams are related to dam type, operating rules, and geomorphic / geologic settings. Understanding the relative importance of each effect allows appropriate studies and research goals to be identified.