Stream restoration and dam removal

Question 1

Geologists have proposed that we are now living in the Anthropocene, a new epoch where human activities dominate Earth system processes. How does this complicate the idea of “restoration”?

Answer 1

• pre-disturbance reference conditions are difficult to find
• climate is changing, which means river hydrology is changing
• lots of eroded sediment due to land clearing for agriculture is stored in river valleys

Question 2

Define stream restoration

Answer 2

assisting in the recovery of an ecosystem after it has been deprived, degraded, or destroyed

Question 3

Goals of stream restoration

Answer 3

1. Make the ecosystem resilient to future changes
2. Return to pre-disturbance conditions
3. Restore ability for rivers to self form (requires dam removal)

as much as possible, we should try to let the rivers restore themselves before taking action

Question 4

What are the steps for productive restoration?

Answer 4

1. Identify pre-existing threat/disturbance
2. Set Goals
3. Forecast effects
4. Set plan into motion and help ecosystem recover

Question 5

Goals of stream restoration include:

Answer 5

• aesthetics
• recreation
• stabilize banks
• reconnect floodplain
• flow improvement
• improve habitat (fish passage)
• dam removal

Question 6

What are fish passages?

Answer 6

requires the removal of dams and inputting fish ladders

Question 7

What is in-stream species management?

Answer 7

introduction of native species and/or removal of exotics

Question 8

What is riparian management?

Answer 8

vegetation or removal of exotic species (i.e. weeds)

Question 9

Water quality management?

Answer 9

change the chemical composition and/or suspended particulate load

Question 10

Muddy river restoration project

Answer 10

• rehabilitation of landscape
• enhancement of aquatic/riparian habitat
• improve water quality
• flood control improvement

Question 11

Which of the following is not a reason for dam removal?

Answer 11

preservation of reservoir recreational opportunities

Question 12

What is an unintended consequence of channelization of any kind?

Answer 12

reduced wetland area = harms habitats and reduces flood storage

Question 13

The first major dam removal in the United States occurred in 1999. What dam was this?

Answer 13

Edwards Dam, Maine

Question 14

What is the primary motivation for recent dam removals in the Kennebec and Penobscot rivers in Maine?

Answer 14

restoration of passage for migrating fish species

Question 15

Which of the following is a goal of the Muddy River restoration project?

Answer 15

• improvement of public park spaces
• traffic flow improvements around Fenway Park
• flood risk mitigation

Question 16

Why remove dams?

Answer 16

1. Public Safety
   - dams are aging and there is a high potential they will break
   - expensive to maintain
2. Outdated Purpose
   - we need electrical based power, not mechanical power anymore
3. Habitat and watershed restoration
   - restore water quality
   - restore fish migration
   - restore habitat

Question 17

What are potential downsides of dam removal?

Answer 17

• flood risk
• increase presence of exotic species and invasive ones = will change ecosystem
• release of contaminants bound to sediment
• sediment release

Question 18

Who initiates dam removal?

Answer 18

Federal Energy Regulatory Commission (FERC)

Question 19

Steps of Dam removal include…

Question 20

What was the Penobscot River Restoration project?

Answer 20

PPL organization work to increase power generation at 6 existing dams
- improve fish passages too

The River Restoration Trust buys 3 hydroelectric dams

Question 21

What were the benefits?

Answer 21

• restores free flow of water and sediment to lower river
• maintains a source of power
• improved fish access to nearly 1,000 miles of river habitat