View from Elyzsian Park, Northeast Los Angeles.
Urban Conservation View from Elyzsian Park, Northeast Los Angeles. © Andrew Hart (Creative Commons/Flickr)

Stories in California

Urban Conservation: Pioneering Solutions in Los Angeles

TNC is working in Los Angeles, the second-largest city in the U.S., to demonstrate what nature can do for cities—and what cities can do for nature.

Though California is known for its iconic natural beauty, nearly 95 percent of residents currently live in urban areas. In the coming years, billions of dollars will be invested to upgrade infrastructure in the urban environment, and we have the opportunity to bring nature into this development.

The Conservancy is focused on using natural infrastructure—infrastructure based on natural systems and processes—to transform how stormwater is managed, which could help address Los Angeles’ water quality and water supply challenges. Examples of natural infrastructure include permeable paving, raingardens and constructed wetlands. These approaches can provide clean water and additional benefits such as habitat, flood protection and clean air.

By using natural solutions to increase biodiversity, reconnect urban communities with nature and secure Los Angeles’ water future, we are creating a new model for urban conservation. The Conservancy is driving change in four major areas: policy, market solutions, science and on-the-ground projects.


The Conservancy seeks to shift the paradigm so that natural infrastructure becomes the default choice over traditional gray infrastructure such as channelized waterways and water treatment facilities. To do this, we are:

  • Pushing for local ballot measures to fund stormwater cleanup with provisions that include natural infrastructure solutions;

  •  Promoting the needed policy changes to facilitate the siting, implementation and maintenance of natural infrastructure; and

  • Advancing the science that demonstrates how natural infrastructure can provide biodiversity, climate resilience and other benefits important to people

Market Solutions

Natural infrastructure is expensive, so we need to help Los Angeles County develop new ways to finance it. We are working to leverage private capital to fund natural infrastructure construction and operations. Two tools, in particular, have demonstrated early promise:

  • Stormwater credit trading, which makes it easier and less costly for property owners to build high-impact natural infrastructure

  • Public-private partnerships, which reduce the cost of government-funded stormwater programs by contracting with private companies to implement a large portfolio of natural infrastructure projects.

Close up of the Los Angeles River
L.A. River Habitat Assessment Close up of the Los Angeles River © © Steve and Julie (Creative Commons/Flickr)

Science and On-the-Ground Projects

The Conservancy is developing the science to ensure that biodiversity is factored into decision making about investments in natural infrastructure.

By making nature an essential part of the equation, we can drive projects that protect and preserve the natural world while improving quality of life for urban residents.

L.A. River Habitat Assessment

The L.A. River is Los Angeles’ most visible stormwater infrastructure and the conduit for most of the stormwater runoff generated in the county. As we advance our Urban Conservation Program, we aim to use the L.A. River to prove that nature and infrastructure don’t have to be at odds—they can reinforce one another. We recently completed a habitat assessment of a 2.5- mile soft-bottom portion of the river to evaluate potential projects. 

Over 12 months, we recorded:

  • More than 100 bird species
  • 17 mammal species, including coyotes and five different bat species; and
  •  7 reptile and amphibian species, including the western toad and Pacific chorus frog.

Our study established an ecological baseline for this stretch of the river, and this knowledge will allow us to understand how best to improve habitat, water supply, and water quality.

L.A. River Pilot Project

We are designing a project to build natural infrastructure in and around the L.A. River. We aspire to create a highly visible new model for urban restoration where habitat, water treatment and public access combine in one place to demonstrate what the future of the L.A. River could be.

Biodiversity Analysis in Los Angeles

We are collaborating with the Natural History Museum of Los Angeles to combine its worldclass community science programs with the Conservancy’s expertise in planning to create a roadmap for deploying natural infrastructure in Los Angeles. Together, we launched “Biodiversity Analysis in Los Angeles” (BAILA), a first-of-its kind map that displays the surprising biodiversity of Los Angeles, even in its most developed neighborhoods. We hope that BAILA becomes a guide for planners and decision-makers by highlighting how infrastructure development has the potential to bring nature back to the city. We also hope it will guide individual project choices by showing developers how making strategic adjustments to their designs can benefit nature.

Safeguarding Our Future

Now is the time to catalyze a new era of urban conservation. By addressing the need for new science, policy and funding frameworks in Los Angeles, the Conservancy aims to create a scalable conservation model that can be applied in cities around the world.