Topanga Lagoon Restoration Frequently Asked Questions

Topanga Lagoon is a special place – it is one of the last remnants of coastal wetland in California. Its unique mix of salt and freshwater habitats act as a natural filtration system to protect water quality, and also hosts some of the rarest of fish and wildlife species. The beach area is not only a popular place to sunbathe and pursue outdoor recreation activities, but also buffers local facilities from storm damage.

Once containing 30 acres of pristine wetlands, Topanga Lagoon has been whittled down to less than 1 acre due to development patterns. By restoring Topanga Lagoon in a coordinated and proactive way, we have the opportunity to preserve the unique biological and cultural resources onsite, while improving flood protection and protecting existing public infrastructure. This project also provides an opportunity to enhance coastal access, expand recreation opportunities, and develop buffers for projected sea level rise.

9. Photo of Historic Development. Looking west over the Topanga Lagoon in the 1900’s prior to extensive development. Photo from the Santa Monica Public Library.

10. Photo of Current Development. Same view of the Topanga Lagoon in 2019. Only a half acre of the lagoon is left. Photo from RCDSMM Stream Team

Some of the specific reasons to restore the Topanga Lagoon include:

• Protect Sensitive Species. Steelhead trout and tidewater gobies are federally endangered fishes on the brink of extinction. They rely on the Topanga Lagoon for habitat and passage. The existing Pacific Coast Highway (PCH) bridge owned by Caltrans that bisects the lagoon is very short and severely limits fish passage (migration) opportunities. Replacing the bridge with one that has a longer span (length) and expanding/improving the wetland and creek habitat will provide better conditions to support these rare fishes. Other sensitive species will benefit by the expansion of open space by providing more areas to feed, rest, bear young, and seek refuge during extreme weather events.

11. Steelhead Trout Rainbow Trout_photo by RCDSMM stream team

Southern steelhead trout differ from rainbow trout as they have spent part of their life in the ocean before returning to freshwater creeks to reproduce.

12. CA Newt in Hand_Photo by RCDSMM Stream Team

13. Two Striped Garter Snake_Photo by RCDSMM Stream Team

14. Tidewater Goby in hand_photo by RCD Stream Team

The fate of these tiny tidewater gobies rests in our hands.

• Counter SLR Impacts. Sea level rise (SLR) and coastal erosion are happening now and are projected to increase in the future. This affects the beach, lagoon and PCH. The lifeguard and restroom building are actively being damaged, and the beach area available to the public and sensitive species is decreasing. These impacts will intensify in the future.

15. Erosion at lifeguard and restroom building 2021_RCDSMM Stream Team

• Identify Future of Topanga Ranch Motel. The historic Topanga Ranch Motel is deteriorating and does not currently provide any visitor services. If feasible, restoration or repurposing could provide potential overnight accommodations or other visitor uses while preserving a part of Topanga history. If habitat restoration of Topanga lagoon requires the removal of the Motel, which is eligible to be listed on the National Register of Historic Places, other cultural resource mitigation may be required.

16. Topanga Ranch motel cabins degrading and unusable 2020_RCDSMM Stream Team

• Improve Visitor Services. Onsite visitor services are limited and would be enhanced by a coordinated plan that addresses parking, a trail system, beach access and interpretation for the entire project site. The existing septic system and other infrastructure are substandard and would be improved to reduce environmental impacts and maintenance costs.

17. Topanga Beach traffic aerial view_RCDSMM Stream Team

Typical Topanga Beach traffic slows down emergency responses to the area.

• Improve Emergency Response. Emergency response to the area is difficult. Enhancing onsite emergency infrastructure would improve response times and resources for land and water incidents during wildfire evacuations.

18. Traffic along PCH during Woolsey Fire_2018 Topanga Democratic Club

We all agree that Topanga Lagoon is an interesting and unique place to visit. We also know that it currently provides a home to many important plants and animals. But upon closer examination, and especially when we look at changes to the lagoon over time, we see that the biological, cultural and recreation resources onsite have been severely damaged. This harm will only increase if we choose not to act.

Topanga Lagoon is one of the only places left in southern California supporting endangered fish species. It is also an important ecosystem for other sensitive plants and animals. We have documented a decline in the number of steelhead trout within the Topanga watershed over time. Increasing the size of the lagoon and the diversity of habitats onsite will provide more resources for not only the trout, but all special-status species. Removing the pinch points caused by the PCH bridge and developed lagoon edges will improve fish migration and restore additional areas for wildlife use. The increased space and habitat diversity will provide more refuge for these species during flood, fire and extreme temperature events. Without action, there is a very real possibility for local extirpation of endangered fish and other species.

19. Steelhead adult looking for a place to spawn 2016_Photo by RCDSMM Stream Team

The Topanga Ranch Motel continues to deteriorate and be an attraction for vandalism. A plan for its restoration, reuse or removal is needed to avoid increasing onsite hazards and maintenance costs, and to make this park gateway more welcoming to park visitors.

20. Topanga Ranch Motel 2020_RCDSMM Stream Team

Existing recreation resources are limited to the beach area, and those that exist are degrading. Coastal erosion is actively damaging the lifeguard building, restrooms, and PCH, while also removing usable beach space. Projected sea level rise will exacerbate these impacts. Unmanaged human use is impacting lagoon water quality – human feces, trash, fire rings, and drug paraphernalia are frequently found floating in the water or washed up on the shoreline. With a restoration plan, the recreational resources of Topanga Lagoon can be better managed and coordinated by the public landowners.

21. Illegal Fire Rings and Encampments at Topanga Beach 2021_RCDSMM Stream Team

We can protect the Topanga Lagoon that we know and love today by directly dealing with the causes of its ongoing decline and projected future threats. The Topanga Lagoon Restoration Plan does that and will also improve coastal access and recreation opportunities.

The Topanga Lagoon Restoration Project recognizes that the Topanga Lagoon is a place of precious biological, cultural, and recreational resources. These assets are threatened not only by current use patterns, but also by projected climate change and associated sea level rise. The Topanga Lagoon Restoration Project is a coordinated multiagency plan that addresses the current causes of resource damage, while proactively building resilience to future environmental challenges. This plan also seeks to improve coastal access and recreation in a way that supports and enhances biological and cultural values.

With help from the TAC and community stakeholders, we identified four alternatives to restore the Topanga Lagoon. We provide a range of alternatives to help decision makers and the public to consider the benefits and challenges of the different restoration approaches. This allows a final alternative to be chosen at the end of the environmental review process that best meet the project’s needs.

Alternative 1 is the “No Project” alternative. It identifies the consequences of what would happen if we choose not to restore Topanga Lagoon.

Alternatives 2-4 are the “Project Alternatives”. Each of these alternatives provides a different road map to restoring the lagoon, buffering its resources from future sea level rise, and meeting the project goals. Under all Project Alternatives the lagoon and riparian areas would be expanded to about 7-10 acres. This would require removing much of the existing fill onsite to create a more natural topography and expanded open space areas. The native fill would be used to nourish adjacent marine areas to provide natural material for area beaches. The lagoon, creek and beach areas would not only be expanded by the restoration, but would be enhanced by replacing invasive plants with native ones. All of these actions will better buffer the lagoon and its resources from the negative effects of projected sea level rise and climate change.

All Project Alternatives would expand the length of the existing 79-foot long Caltrans bridge to 460 feet to improve fish migration and the quantity/quality of lagoon habitats. A plan for the Topanga Ranch Motel, locations for appropriate concessions and improved parking would be included for all alternatives. Prehistoric cultural sites would be protected in place. Coastal access and interpretive elements would be included in all alternatives. This includes pedestrian access under PCH on the east and west sides of the lagoon, and emergency vehicle access on the east. The lifeguard building and beach restrooms and emergency facilities would be relocated further from the beach edge to improve emergency response, and better protect them against storm surges and sea level rise..

A summary of each alternative is below. A more detailed description of each, and the objectives behind them, will be available in the environmental documents prepared for the project.

Alternative 1: No Project/Managed Decline (0 acres restored): There would be no change to the lagoon footprint or habitat quality and no new bridge. The lifeguard building would continue to be undermined from coastal erosion and sea level rise and emergency access would be further constrained. The Topanga Ranch Motel would be left in its non-operational state. The existing non-conforming concessions and septic systems would not be improved and their future use could be restricted. No improvements to habitat would occur. Sea level rise will continue to reduce the beach area, and threaten PCH and onsite structures.

22. The Project Area. The Topanga Lagoon Restoration project area is managed by CA Dept of Parks & Rec within Topanga State Park (N of the PCH), CA Dept of Trans (area highways) & LA County Depart of Beaches & Harbor

Existing Conditions within the project area would not be improved under Alternative 1.

Alternative 2: Lagoon Habitat Maximized, Removal of Motel (~9.5 wetted acres, plus ~6.1 riparian acres restored): This alternative provides the maximum amount of lagoon, wetland, riparian and transitional habitat, but totally removes the historic Topanga Ranch Motel and other visitor services from the project area. This alternative includes restoration of more natural side channels of different elevations on the west side of the existing creek that are based on the historic configuration of the lagoon. These channels would accommodate changing sea level and storm surge conditions.

An improved bus stop, trail system, and visitor amenities would be developed. North of PCH: Visitor services and parking would be developed along the west side of Topanga Canyon Boulevard and along PCH and would likely be supported by a new onsite wastewater treatment system. A single concession (in the location of the existing Reel Inn restaurant) is kept. South of PCH: Parking would be improved, and the lifeguard building and helipad would be relocated for better emergency response and protection from storm damage.

23. Alternative 2 Conceptual Development Topanga Lagoon Restoration Project_02.2023

Alternative 3: Least Lagoon Habitat Expansion, Full Retention of Motel (~7.7 wetted acres, plus ~6.3 riparian acres restored): This alternative preserves much of the Topanga Ranch Motel in its historic configuration and allows for the retention of one concession (in the location of the existing Reel Inn restaurant), while also providing expanded lagoon, wetland, riparian and transitional habitat mostly on the west.

An improved bus stop, trail system, and visitor amenities would be developed. North of PCH: Visitor services and parking would be developed along the west side of Topanga Canyon Boulevard and along PCH and would likely be supported by a sewer connection. South of PCH: Parking would be improved, and the lifeguard headquarters and helipad would be relocated for better emergency response and protection from storm damage.

24. Alternative 3 Conceptual Development Topanga Lagoon Restoration Project_02.2023

Alternative 4: Maximum Managed Retreat, Partial Motel Retention (~7.6 wetted acres, plus ~6.2 riparian acres restored): The alignment of PCH moves north permitting the maximum amount of beach area and protection of structures from sea level rise. A portion of the historic Topanga Ranch Motel is retained with parking adjusted and allows for remodel and continued operation of a concession (in the location of the existing Reel Inn restaurant) while also providing expanded lagoon, wetland, riparian and transitional habitat mostly on the west.

An improved bus stop, trail system, and visitor amenities would be developed. North of PCH: Visitor services and parking would be developed along the west side of Topanga Canyon Boulevard and along PCH and would likely be supported by a sewer connection. South of PCH: Parking would be improved, and the lifeguard building and helipad would be relocated for better emergency response and protection from storm damage.

25. Alternative 4 Conceptual Development Topanga Lagoon Restoration Project_02.2023

It should be noted that some of the options included in a specific alternative could be “mixed and matched” to create the best alternative feasible. This includes full or partial retention of the Topanga Ranch Motel, inclusion of more than one wetted lagoon channel, and expanding existing beach area through bridge realignment to the north. The extent to which differing priorities are implemented will ultimately depend upon landowner needs, environmental considerations, and public feedback.

The Topanga Lagoon Restoration Project will be successful for several reasons. Using the best available scientific tools, we have designed a project that thoroughly understands the history of the lagoon, how it has changed over time, and the challenges that threaten its resource values both now and into the future. Extensive feedback from the public, resource agencies and technical experts has helped determine realistic and preferred goals for the restoration in the areas of biological, cultural, and recreation/visitor services resources. The project consultants Moffatt & Nichol engineers and Environmental Services Associates (ESA) both have significant experience successfully designing and completing similar coastal lagoon restoration projects in Southern California, including Malibu Lagoon, Los Cerritos lagoon and Los Peñasquitos lagoons.

The project team solicited extensive stakeholder participation, which led to the development of the design alternatives that incorporated their recommendations. Stakeholders determined that the project needs to:  

• increase wetland, riparian and transitional suitable habitat to support existing and future biodiversity
• provide space for the creek and lagoon to adjust and adapt to changing conditions of sea level rise and reduce coastal erosion over time
• avoid any impacts to the surf break
• reduce flood risk
• protect the existing habitat during construction
• avoid any impacts to the sensitive archaeological resources
• improve coastal access for recreation
• improve emergency and safety access

The design of the restored lagoon and changes to the beach morphology are based on modeling validated by real data collected since 2001. This extensive data set was used to calibrate the hydrology/hydraulic analysis. State of the art sea level rise models were used to evaluate how the system will respond over time.

• Winter 2023 Baseline Studies. Complete background technical studies and develop 30% alternative designs.
• Winter 2024 Environmental Review. Prepare and circulate the Draft Environmental Impact Report/Environmental Assessment (EIR/EA) including public meetings. Respond to comments, select a preferred alternative, and complete Final EIR/EA.
• 2024-2026 Design Phase. Complete engineering design for the preferred alternative and complete permit applications.
• 2027-2030 Construction.
• 2030-2035 Post-Construction Monitoring.

The Resource Conservation District of the Santa Monica Mountains (RCDSMM) is under contract with the California Department of Parks and Recreation (California State Parks) to coordinate the restoration planning phase. The other landowners, California Department of Transportation (Caltrans) and Los Angeles County Department of Beaches and Harbors (DBH) are also collaborating in this process. A Technical Advisory Committee including representatives of all permitting agencies, local wetland restoration experts and the landowners provides direction and constraints to ensure that the project meets all requirements.

Moffatt & Nichol engineers, Chris Nelson and Associates, and Environmental Services Associates (ESA) have provided design, engineering and modeling support. The National Park Service, Santa Monica Mountains National Recreation Area has provided technical support on special-status species issues. Many expert consultants have been engaged to provide technical expertise about onsite biological and cultural resources, and geological characteristics.

26. Topanga Lagoon Restoration Team

The project will be reviewed per the requirements of the California Environmental Quality Act (CEQA) and National Environmental Policy Act (NEPA), During this process, the lead agencies (California State Parks and U.S. Army Corps of Engineers) will complete preparation of the required environmental documents that analyze the potential of the project and its various alternatives to affect the human and natural environment. The public and regulatory agencies have an opportunity to comment on the project during several points in the process, including during the 60-day public comment period. The lead agencies will consider public and agency comments, consult with involved landowners (Los Angeles County Department of Beaches and Harbors and Caltrans) to finalize the document, and identify and approve a preferred alternative.

27. EIR Review Process_sonomasun.com

Arrows show the periods where public involvement typically occurs. The Notice of Preparation/Scoping Meeting occurred in June 2022. The Draft EIR will be released in early 2024 with a 60-day comment period.

The project will also require multiple permits/approvals from other regulatory agencies that have jurisdiction over elements of the project. These approvals will identify specific conditions that must be met for the project to be implemented. Approvals required for this project include: California Coastal Commission (consolidated Coastal Development Permit), California Department of Fish and Wildlife (Streambed Alteration Agreement), USACE (404 Permit), Regional Water Quality Control Board (401 Authorization), Los Angeles County, among others.

Public stakeholder meetings will be held periodically as the Topanga Lagoon Restoration project evolves. Please follow the status of the project by going to the Topanga Lagoon webpage and checking the What’s New section. You can sign up to receive email updates about the project directly on the Stay Connected page.

The Planning and Environmental Review phases have been fully funded by the landowners, grants from public resource agencies, and in-kind support. Design funding has been secured for the bridge and lagoon restoration. We are still looking to secure funding for design of visitor serving elements. Current funding support includes:

• State Coastal Conservancy, $1,6M for planning
• California State Parks $540K, visitors services analysis
• Caltrans, over $3 million in-kind engineering and environmental review
• California Department of Fish and Wildlife, $1.6M, environmental review, public outreach
• Wildlife Conservation Board $4M, additional coastal morphology, nearshore transport and marine environment studies, environmental review, Caltrans Project Report, public outreach.

Upon completion of the environmental documents, the preferred alternative will be chosen and the Final Engineering and then Construction phases can be initiated. Funding for to take the bridge and lagoon restoration elements to final design and permitting is provided through the state legislature and administered by the Wildlife Conservation Board.

28. Topanga Lagoon Funders

According to records from the Los Angeles County Lifeguards, there are up to 1 million visitors a year using Topanga Beach.

There are two public landowners that manage the lagoon. The area south of the Pacific Coast Highway (PCH) belong to Los Angeles County Department of Beaches and Harbors. The area north of the PCH is within Topanga State Park and is managed by California State Parks.

California State Parks. It is a historic district within Topanga State Park.

The motel buildings have been evaluated and determined to be eligible for listing on the National Register of Historic Places/California Register of Historical Resources due to being a rare surviving example of the transition from pre-war auto camp to post-war roadside motel. However, these deteriorating buildings must be brought into compliance with environmental standards for foundation, mold, asbestos, lead paint and septic. California State Parks is conducting a study to evaluate if it is possible, and economically feasible, to restore some of the buildings and implement the required upgraded wastewater management. If it is determined to be feasible to restore some or all of the buildings, California State Parks needs to determine the potential uses of the structures, and whether they will remain in their current location, need to be relocated to another area to accommodate the habitat restoration, or be demolished. Funding needs to be secured for the design and construction phases to address the fate of these structures onsite.

All the businesses on the north side of PCH are managed as business leases by California State Parks. Businesses are required to be compatible with approved onsite uses and avoid impacts to protected resources. Contact States Park at (818) 880-0363 for more information.

For thousands of years the project area was home to the Gabrielino Tongva tribe. There are records of a small seasonal village at the mouth of Topanga Creek. Historic records and limited excavations over the years have documented a history of site occupation by these Native Americans.

In 1804 the project area became part of the Rancho Topanga Malibu Sequit land grant awarded to Jose Tapia. Historic records (1876 T-sheets and 1920s aerial photos) suggest that the dendritic channels in the saltgrass (Distichlis spicata) dominated wetlands were seasonally dry, and the deeper channel trended towards the west side of the lagoon. Although we understand that it is not possible to fully restore the once 30-acre lagoon, we used this data to inform our restoration design process.

29. Historic Topography. 1876 T- sheet map of Topanga Lagoon_Image from the University of California at Santa Barbara Library

30. 2019 aerial of Topanga Lagoon overlaid with outline from the 1876 T sheet_RCDSMM

Starting with the building of local roads in the early 1900s, a wooden trestle bridge was installed at what was then the transition from the almost 30-acre lagoon to the creek channel. The pilings from that bridge are still present and located approximately 300 ft upstream of the current PCH bridge. Farming on the eastern edge of the wetland area also began around that time.

31. 1920’s view of Topanga Lagoon_Photo courtesy of the Randy Young Collection

In 1919, a beach campground was established to serve the increasing numbers of recreational users at Topanga Beach. A dance pavilion and tent cabins were constructed and managed by Miller and Archie Cooper and became known as Cooper’s Camp. The Los Angeles Athletic Club purchased the recreational area in 1924. In 1927, the state began the construction of the Roosevelt Highway along the coast through the Malibu Rancho. In 1933, the highway was realigned and the original bridge was replaced with the much shorter current 79-ft span box culvert with two bays and a concrete bottom, and at least 25 ft of fill was added at the four bridge abutments, effectively leaving less than an acre of lagoon habitat surrounded by steep banks. The cabins of the former Cooper’s Camp were salvaged and the Topanga Beach Auto Camp was built on top of the fill. This evolved into the Topanga Ranch Motel after World War II, and the motel, along with surrounding leased cabins became more of a permanent residential community.

32. 1930 Highway re-alignment showing the Topanga Ranch Motel in upper right_Spence Collection UCLA

All of the structures on the south side of PCH were removed in the 1970s when California State Parks took ownership of Topanga Beach. Ownership of the beach was subsequently transferred to LACDBH in the late 1980s, and the existing lifeguard/restroom building and parking lots were built. This is a very popular recreational destination serving almost a million visitors a year with a well-known surf break.

California State Parks began planning and some preliminary cleanup activities for the lagoon area of Topanga State Park in the early 2000s. By this time the lagoon had shrunk to half an acre, had high levels of disturbance and was constrained on both east and west sides by 30-ft tall fill banks supporting development. Most of the rental cabins and businesses onsite north of PCH were removed due to deterioration and septic tank leakage directly into the lagoon and ocean. The Topanga Ranch Motel was closed with only one building left in use as a staff residence (with the septic tank enclosed and pumped). The several businesses that remain as concessionaires require weekly septic pumping as all of the leach fields have been sealed.

Topanga Beach often gets an F rating by the Heal the Bay Beach Report Card during the wet season. A study completed in 2015 by the RCDSMM and UCLA found that the source of the bacteria was primarily birds and dogs. Human feces from “direct deposits”, as well as human encampments on the beach and around the lagoon, also contribute to deteriorated water quality.

The town of Topanga eight miles uphill is not contributing to the problem at this time.

33. Birds at Topanga Lagoon_RCDSMM Stream Team

34. Dog poop at Malibu Lagoon_RCDSMM Stream Team

Local septic systems were not identified as a contributing problem in the 2015 report, however the closed septic systems used by the onsite ranger residence within the Topanga Ranch Motel and concessions on the north side of PCH are non-compliant and require frequent pumping. Improving these systems will be addressed during the environmental analysis.

Alternatives 2-4 will all increase the size of the beach by moving the access road inland and removing the fill on the west side of the lagoon. Alternative 4 creates the most beach space by moving the Pacific Coast Highway bridge slightly north. Actual acreages for beach space will be identified for each alternative in the project environmental documents.

ADA access is maintained as part of each alternative.

No change to the surf break or beach berm is expected under any alternative. The restoration excavation will not occur on the existing beach berm that separates the lagoon and ocean. There will be no change to the natural breaching pattern, which is driven by storm events. The project is not expected to affect the existing cobble dominated shoreline which is responsible for the surf conditions. A study is being conducted to assess the potential of the project to affect the beach morphology and surf conditions.

35. Surfers at Topanga Beach in 2021_RCDSMM Stream Team

Parking is currently free along the road shoulders of the Pacific Coast Highway and Topanga Canyon Boulevard and some free shoulder parking will be retained, but the existing conditions do not meet current code requirements. We are currently analyzing future parking opportunities, but it is not yet clear how much of it will be free.

Prior to the start of construction, a new parking and interpretive area will be developed along Topanga Canyon Blvd. The bus stops will be improved to make them more visible and welcoming. New stairs will be added to make beach access near the intersection safe and provide closer access to the east cove beach.

We do not know yet. California State Parks is examining the feasibility of upgrading current and future septic systems to meet visitor serving needs. These costs will be compared to the cost of connecting to the sewer that is located one mile east of the property.

We do not expect traffic to significantly worsen during construction. One of the requirements of the project is to ensure that the existing four lanes of traffic are maintained during construction by constructing a temporary bridge. The only exception would likely be during the short periods of time when equipment is moved on or off site. There will also be tight restrictions on construction during red flag events to avoid impacts to emergency response. The environmental document for the Topanga Lagoon project will fully analyze potential changes to construction related traffic.

Whether the project will generate additional visitors and longer-term traffic impacts is unknown at this time as the ultimate development of visitor services facilities on site has not yet been determined. California State Parks is completing a Visitor Services and Overnight Accommodation study to determine whether the Topanga Ranch Motel can be feasibly restored or repurposed. Returning it to a functional motel or reusing portions of it as a visitors’ center are being considered. Improved parking is also being proposed as part of the plan. The potential effects of these project elements will be addressed for each project alternative within the Traffic and Public Recreation sections of the EIR/EA.

Similar lagoon restoration projects in Southern California have taken 3-5 years. Construction can be initiated once the planning and engineering phases are completed and funding is acquired.