Course Conclusion

Ecological values depend on natural riverine processes including:

Flow, transport of sediment, nutrients, and organic matter

Riverine species depend on longitudinal connectivity in the way of…

Up and downstream movement of water sediment, organisms

Riverine species depend on lateral connectivity in the way of…

Between channel and floodplain

Riverine species depend on vertical connectivity in the way of…

Between surface and groundwater

Can there be ecology in urban river revitalization?

Often assumed to be impossible, but it may be an excuse to not even try. Lack of expertise in those who carry out riverfront revitalization makes it difficult.

Riverfront revitalization efforts are typically run by an…

Economic development department of the city, without expertise in ecology or fluvial processes.

Can there be equity in urban river revitalization?

Projects focus on reconnecting urban population with riverbanks, but poor people may be ‘invisible’ to these project proponents, may be seen as ‘in the way’ of redevelopment.

Social connectivity definition

The communication and movement of people, goods, ideas, and culture along and across rivers.

The Seine River in Paris

Its lateral social connectivity was sacrificed by 1850 for navigation, to make the river a ‘national river.’ Laundries, tripe merchants, tanneries, small boat landings were removed.

We can define different uses of rivers as…

A function of elevation above the water and degree of activity.

Everyday human uses of urban rivers

Washing clothes

Subsistence fishing

Streamside farm plots

Transportation by ferries

Religious observance

Recreation

Canoeing and kayaking

Urban swimming

Rivers need width

Restoring true river process usually requires giving the river some space in which to actively flood, erode, deposit, and migrate.

This may be difficult to achieve in dense urban environmentals, conflicts with goal of maximizing urban area. Engineered channels have been built to maximize urban development, often with buildings and infrastructure right up to the edge of the channel.

To provide the river with more space requires removing some buildings! Very expensive.

The service life of a concrete channel is….

75 years

Given the typical service life of a concrete channel…

Since they were mostly built in 1950 - 1990, they will be expiring in the middle of the current century.

Contra Costa County Plan

Adopted in 2009. Committed to a goal of converting its concrete channels to natural channels over the next 50 years. It supports cities in integrating policy into land-use plans.

We want to create river corridors

Within which the river can erode, deposit, flood, connecting channel, bank, floodplains, hyporheos

A river corridor is for ________ and ________ not just floodwaters

fluvial erosion and deposition