Nature-Based Solutions
The use of nature-based solutions is not a new concept, but it has received a new importance in environmental management in the United States and throughout the world in recent years. Our indigenous ancestors used nature wisely to control fires and enhance habitat. In Los Angeles County, the Safe Clean Water Program, which has provided more than $7 million in funding for the Arroyo Seco Water Reuse Program, emphasizes and prioritizes the use of nature-based elements. It has recently established a task force to better define nature-based solutions and ensure their implementation.
Regrettably, the Arroyo Seco Water Reuse project, proposed by the cities of Pasadena and South Pasadena, generally fails to employ nature-based approaches.
Restoring natural stream hydrology through nature-based solutions involves using natural or modified ecosystems to address challenges related to water management, climate change, and biodiversity. Instead of relying on costly engineering facilities, the nature-based approach focuses on restoring and replicating natural processes and features to achieve a variety of benefits, including improving water quality, enhancing habitat, and increasing the resilience of ecosystems to the effects of climate change.
The confluence of San Rafael Creek and the Arroyo Seco is an ideal site for an award-winning project involving natural stream restoration and wetlands in the area nearby. Only a small section of the Creek near the Arroyo is lined with concrete that should be removed. A natural approach would greatly enhance the area and be beneficial to recreational users, native fish, and wildlife.
The flood channel in the Arroyo Restoration Corridor (ARC) has severely deteriorated and does not have the capacity for the substantial floods that should be anticipated in the era of climate change. A natural approach would remove large sections of the flood channel lining and reclaim some of the historic flood plain.
Key Principles
Replicating Natural Systems:
Nature-based solutions aim to replicate natural processes and features, such as wetlands, riparian zones, and floodplains, to manage water resources effectively.
Restoring Natural Hydrological Functions:
This includes actions like reconnecting floodplains, restoring wetlands, and reforesting riparian zones to improve water storage, reduce erosion, and enhance water quality.
Enhancing Ecosystem Resilience:
By restoring natural processes, these solutions can help ecosystems adapt to changing conditions, including those related to climate change, such as increased droughts or floods.
Multiple Benefits:
Nature-based solutions offer a range of benefits, including water management, climate change mitigation and adaptation, biodiversity conservation, and improved human health and well-being.
Examples
Wetland Restoration:
Wetlands can store excess water during floods, filter pollutants, and provide habitat for various species.
Riparian Buffer Zones:
These vegetated areas along streambanks can improve water quality by filtering runoff, reduce erosion, and provide habitat for wildlife.
Floodplain Reconnection:
Reconnecting floodplains allows streams to spread out during high flows, reducing flood risks downstream. Steps can include the removal of concrete and the establishment of storage and percolation zones.
Natural Infrastructure in Dryland Streams:
Structures like log dams and weirs can improve water availability and create habitat in arid regions.
Benefits
Cost-Effectiveness:
In many cases, nature-based solutions can be more cost-effective than traditional engineering solutions, particularly for long-term water management and ecosystem restoration.
Reduced Maintenance Requirements:
Nature-based solutions generally have considerably lower long-term maintenence requirements and costs.
Sustainability:
They promote sustainable water management practices by relying on natural processes and features.
Multiple Ecosystem Services:
Nature-based solutions provide a wide range of ecosystem services, such as water purification, carbon sequestration, and biodiversity conservation.
Arroyo Seco Community Benefits
The nature-based approach can enhance recreational opportunities, restore habitat, improve water quality for drinking and irrigation, and contribute to the overall well-being of Arroyo Seco communities.
In the Arroyo Seco, nature-based solutions could include wetlands restoration, removing large amounts of concrete from the flood channel and stream, restoring parts of the historic floodplain, and improving conditions for birds and wildlife through habitat restoration.
Nature-based solutions, particularly in the urban stretch of the Arroyo Seco, will be critical for dealing with climate change and promoting biodiversity in our region. They should include protections for fish and wildlife and enhance native habitat.