This investigation focuses on potential improvements to the Blake Garden section of Cerrito Creek for both ecological and social reasons. Cerrito Creek runs through an urbanized watershed from the East Bay Hills to San Francisco Bay. Garden staff recently cleared nonnative invasive Himalayan blackberry (Rubus discolor) from several sections of the streambank, leaving it barren. We identified bank erosion and incision resulting from recent clearing and upstream urbanization as two issues to be addressed. The garden staff identified creek visibility and accessibility as their main concerns. To assess existing creek conditions and restoration objectives we completed longitudinal and cross sectional surveys, measured discharge from an on-site spring, and conducted interviews. We calculated creek discharge using the rational method, measured the surface area of two rooftops to estimate stormwater runoff, and measured discharge from a natural spring in the garden. Based on our assessment, we developed a creek restoration plan that addresses the hydrologic issues we identified, concurrently with those set by the garden staff. Our short-term recommendations include: jute netting and stream-bank plantings to stabilize the banks, constructing a step pool to reduce energy and provide an aesthetic water feature, and installing rain and stream gauges. Long-term recommendations include: geotextile reinforcement and regrading steep banks to improve access and safety, replacing downstream check dams with step pools, removing concrete (substituting alternative stabilization measures), reducing stormwater runoff onsite, and water harvesting from the natural spring. Future studies should monitor the rate of incision, evaluate the effectiveness of restoration measures, and assume an adaptive management approach.

There are many sources of urban river degradation from channel straightening and culverting for flood control and development, to point and non-point source pollution, and altered flow regimes due to urbanization and increased impervious surfaces. In this study, we focus on the hydrologic impact of impervious surfaces in an urban watershed in the East Bay area. We used the Water Framework Directive (WFD), recent legislation in Europe, to understand how a watershed approach and systematic waterbody characterization can guide restoration efforts. Specifically, we applied the WFD to Sausal Creek Watershed and developed a conceptual restoration plan that incorporates watershed-scale low impact designs (LID) to restore a natural flow regime and in-stream restoration to enhance the physical habitat. We modeled the change in runoff due to urbanization, and calculated the total area required to mitigate for stormwater. Our results show a nearly two-fold increase in peak flow from pre-development to today. To mitigate for increased impervious surfaces 38-57% of the basin would need to drain to LID sites. We compared the cost of LID with the cost of in-stream restoration and found in-stream restoration of the entire three mile channel would be equivalent to treating one-sixth of the watershed with LID. Finally, we developed a short-term and long-term program of measures to restore Sausal Creek.

Society is investing in river restoration and urban river revitalization as a solution for sustainable development. Many of these river projects adopt a multifunctional planning and design approach that strives to meld ecological, aesthetic, and recreational functions. However our understanding of how to accomplish multifunctionality and how the different functions work together is incomplete. Numerous ecologically justified river restoration projects may actually be driven by aesthetic and recreational preferences that are largely unexamined. At the same time river projects originally designed for aesthetics or recreation are now attempting to integrate habitat and environmental considerations to make the rivers more sustainable. Through in-depth study of a variety of constructed river landscapes - including dense historical river bend designs, artificial whitewater, and urban stream restoration this dissertation analyzes how aesthetic, ecological, and recreational functions intersect and potentially conflict.

To explore how aesthetic and biophysical processes work together in riverscapes, I explored the relationship between one ideal of beauty, an s-curve illustrated by William Hogarth in the 18th century and two sets of river designs: 18th century river designs in England and late 20th century river restoration designs in North America. I used two quantifiable variables, sinuosity and symmetry, to compare the ideal curve of beauty to the designed river curves. Hogarth's s-curve and river restoration meanders had symmetrical curves. Symmetry in restoration designs represents a theoretical condition and is counter to how most natural rivers meander. A second aesthetic-ecological study examined whether 18th century English landscape design represents design with nature. By tracing the persistence of Capability Brown's river designs over the past two centuries, the results show Brown's designs required maintenance and are not self-perpetuating as expected of a design based on natural processes.

To evaluate the intersection of recreation and ecological functions, I conducted a case study of three urban river projects, a historical study of artificial whitewater designs, and an observational study of summertime whitewater park use. By comparing the ecological and social impacts of three urban river projects (Cheonggyecheon in Seoul, South Korea, the South Platte Greenway in Denver, United States, and the Isar River in Munich, Germany), one emerged as moving towards multifunctional planning and design. The Isar River project was unique because the planners and designers used a dynamic guiding image, gave the river room to roam, and allowed some dynamic biophysical processes to occur. The selection of the guiding image for the Isar restoration was fortuitously a publicly valued stream reach for its aesthetics and existing recreational use. The South Platte Greenway, which contains a whitewater park, illustrates a riverscape made primarily for recreation. The history of artificial whitewater designs evolved since the 1970s to a point in 2000 when the Sydney Olympic Whitewater Course was disconnected from a stream to create a fair playing field for competitors where all of the whitewater variables could be controlled. Meanwhile, instream whitewater parks began to include habitat and fish passage considerations in the engineered wave structures. Observations of whitewater park use and surveys of park user's perceptions of the parks revealed that kayakers represent only a small fraction of park users and overall use evinced no clear relationship to streamflow but varied with air and water temperature. Summer streamflow provisions for whitewater parks potentially limits the diversity of instream users and the ecological function. While whitewater park users value clean water as the most important characteristic, all interviewed park users wanted the park to have a natural appearance, but they did not mind seeing concrete in the river.

Understanding the patterns of recreation and perceptions of rivers in relation to biophysical processes such as streamflow or channel pattern is fundamental to achieving sustainability. The forms that people prefer--perhaps because they are beautiful--and a local-level understanding of recreational use need to be considered alongside the physical and ecological patterns and processes of rivers, the domain of landscape ecology and river science. Combining ground level research and perception studies with environmentally based landscape planning can create multifunctional landscapes. For previously impacted rivers in developed areas, multifunctional riverscape planning and design offers a sustainable development solution.

The Lisbon metropolitan region has grown rapidly in population since 1970, due largely to the immigration of people from former Portuguese colonies in Africa and from rural areas of the country in pursuit of higher living standards. Much of this population growth was accommodated clustered high-rise apartment blocks (many unpermitted) in the region west of Lisbon, in the municipalities Oeiras, Cascais, Sintra, and Amadora. These developments were largely unplanned, often did not provide for sewage treatment, and lack adequate mass transit or urban amenities such as parks and other open spaces. Moreover, because the main transport axes run east-west, it is difficult for residents of these apartment blocks to go the relatively short distance southward to the coast (e.g., only 10 km from Cacém to the coast).

This region is drained by a set of subparallel streams (each draining about 20-50 km2), flowing roughly north-south through deeply incised valleys to debouch into the Atlantic between Lisbon and Cascais. With rapid urbanization peak runoff has increased, resulting from larger impervious surfaces and sewage from illegal housing settlements. Many reaches have been canalized within concrete walls to increase flood capacity, eliminating physical habitat complexity, and reducing amenity and recreational values. However, the urbanization has occurred mostly on uplands, leaving the bottomlands of the incised stream valleys in many reaches surprisingly unaltered. For decades, these drainages were largely neglected, managed mostly to convey floodwaters, although in some reaches there was strong informal use of the stream corridor and floodplains (such as garden plots). The Water Framework Directive (WFD) adopted by the EU Parliament (2000), has motivated extension and improvement of the regional sewer network to improve water quality. The WFD requires that all water bodies in member states achieve ‘Good Ecological Status’ by 2015, defined in terms of hydromorphological, biological, and physico-chemical quality elements of stream reaches, based on characteristics documented at reference sites.

Located 15 km west of Lisbon, Ribeira da Barcarena-Jardas drains a 35 km2 catchment, whose uppermost reaches are forested, but otherwise alternates between urbanization and remnant agricultural and open-space uses. With improved sewage treatment and water quality, there is strong potential to preserve and restore ecological functions, consistent with goals of ‘good ecological status.’ As illustrated by the successful urban stream project in Cacém, there is tremendous potential for the stream corridor to provide parkland for the dense urban settlements. Through GIS analysis of remotely-sensed data, and field surveys of water quality, habitat structure, riparian vegetation, and fish populations, an interdisciplinary workshop of graduate students from Berkeley and Lisbon analyzed potential opportunities to enhance ecological values and human access along the stream. Our analysis indicated that implementation of stormwater management strategies via relatively unobtrusive retrofits of small open bits of urban land and floodplain within the catchment could mitigate many of the negative hydrologic effects of urbanization. By virtue of its linear nature, the stream corridors could provide pedestrian and bicycle connections from population centers (now under-served by parklands) to cultural features and to coastal beaches and trails. A trail could inspire similar efforts on neighboring, parallel basins that have undergone similar urbanization pressures and face similar challenges in providing underserved urban populations with access to recreation and contact with nature.

The Lisbon metropolitan region has grown rapidly in population since 1970, due largely to the immigration of people from former Portuguese colonies in Africa and from rural areas of the country in pursuit of higher living standards. Much of this population growth was accommodated clustered high-rise apartment blocks (many unpermitted) in the region west of Lisbon, in the municipalities Oeiras, Cascais, Sintra, and Amadora. These developments were largely unplanned, often did not provide for sewage treatment, and lack adequate mass transit or urban amenities such as parks and other open spaces. Moreover, because the main transport axes run east-west, it is difficult for residents of these apartment blocks to go the relatively short distance southward to the coast (e.g., only 10 km from Cacém to the coast).

This region is drained by a set of subparallel streams (each draining about 20-50 km2), flowing roughly north-south through deeply incised valleys to debouch into the Atlantic between Lisbon and Cascais. With rapid urbanization peak runoff has increased, resulting from larger impervious surfaces and sewage from illegal housing settlements. Many reaches have been canalized within concrete walls to increase flood capacity, eliminating physical habitat complexity, and reducing amenity and recreational values. However, the urbanization has occurred mostly on uplands, leaving the bottomlands of the incised stream valleys in many reaches surprisingly unaltered. For decades, these drainages were largely neglected, managed mostly to convey floodwaters, although in some reaches there was strong informal use of the stream corridor and floodplains (such as garden plots). The Water Framework Directive (WFD) adopted by the EU Parliament (2000), has motivated extension and improvement of the regional sewer network to improve water quality. The WFD requires that all water bodies in member states achieve ‘Good Ecological Status’ by 2015, defined in terms of hydromorphological, biological, and physico-chemical quality elements of stream reaches, based on characteristics documented at reference sites.

Located 15 km west of Lisbon, Ribeira da Barcarena-Jardas drains a 35 km2 catchment, whose uppermost reaches are forested, but otherwise alternates between urbanization and remnant agricultural and open-space uses. With improved sewage treatment and water quality, there is strong potential to preserve and restore ecological functions, consistent with goals of ‘good ecological status.’ As illustrated by the successful urban stream project in Cacém, there is tremendous potential for the stream corridor to provide parkland for the dense urban settlements. Through GIS analysis of remotely-sensed data, and field surveys of water quality, habitat structure, riparian vegetation, and fish populations, an interdisciplinary workshop of graduate students from Berkeley and Lisbon analyzed potential opportunities to enhance ecological values and human access along the stream. Our analysis indicated that implementation of stormwater management strategies via relatively unobtrusive retrofits of small open bits of urban land and floodplain within the catchment could mitigate many of the negative hydrologic effects of urbanization. By virtue of its linear nature, the stream corridors could provide pedestrian and bicycle connections from population centers (now under-served by parklands) to cultural features and to coastal beaches and trails. A trail could inspire similar efforts on neighboring, parallel basins that have undergone similar urbanization pressures and face similar challenges in providing underserved urban populations with access to recreation and contact with nature.