Just where Tomales Bay meets the Pacific Ocean lies Marin County's least-known ecological treasure, Tomales Dunes, the largest unprotected dune system in central California. Tomales Dunes is actually a complex of several distinct habitats: mature mobile dunes, central dune scrub, dune prairie, and dune wetlands. And it is surrounded by and connected to a rich coastal environment that includes coastal prairie, coastal scrub, salt marsh, tidal flats, bay, and ocean. This extraordinary site, which includes a 230 foot high dune known as Little Sugarloaf, supports at least 17 rare, threatened, or endangered species.
Tomales Dunes is responsible for much of the unique character of Tomales Bay and the surrounding area. It provides a buffer to the prevailing westerly winds and modifies the tides, creating a relatively protected bay, one that is more complex, hospitable, and biologically diverse than a simple marine inlet. In addition, its rich variety of dune and coastal environments adds to the diversity of habitats in the Bay, making it a year-round home and an important migratory stop-over for a variety of bird species. More than 40 species of waders and waterfowl, for example, find their winter roosting and feeding grounds at Tomales Dunes. It is, for example, one of only eight sites in North America where Pacific golden plovers (Pluvialia fulva) overwinter.
The aggressive alien, European beachgrass (Ammophila arenaria) , which dominates nearly all other California dune systems has not yet overtaken Tomales Dunes, though it is threatening to do so. So far, however, this still is one of the few dune systems in California that has a vital population of native dunegrasses. including a recently discovered and still-undescribed species. In addition, there are mobile dunes here, the kind we think of when we call to mind the classic dune-completely unvegetated and constantly shifting. As winds push these mobile dunes slowly inland, an ever-changing series of new habitats is created.
Winds also carve depressions in the exposed sands of the bare dunes. Where these depressions are fed by groundwater, rain, or intermittent surface streams, they develop into rich and unique seasonal wetlands, ranging from freshwater ponds, to marshes, to wet meadows". Tomales Dunes is a wetland paradise, with the richest collection of these seasonal wetlands--known collectively as "dune slacks"--in central California. The same subterranean waters that feed the slacks have also created an amazing "Grand Canyon of the Sands", which is recut and reshaped in wet winters by a rain-fed underground spring, the only such dune canyon in central California.
Tomales Dunes is an ancient system, but one that is perpetually forming itself anew. Some of its dunes are very young, having developed in historic times; most are older, created after the last ice-age; and some may have originated even earlier, perhaps more than 10,000 years ago. In the last few decades, this ancient system has come under increasing pressure from ranching, quarrying, and recreation. How much longer can Tomales Dunes survive?
CURRENT USE
Tomales Dunes is the only dune system in the state that is wholly in
private ownership. Most of this incredible site is within the 980-acre
property known as Lawson's Landing, which has been in the Lawson family
since the 1920s. Lawson's Landing includes a ranch, a sand quarrying operation,
and a recreation area featuring an RV campground and boat storage and repair
facilities.
The ranching operation, Lawson's Livestock, has roughly 100 cattle and 765 sheep. The animals range beyond the property's 550 acres of pasture onto more fragile habitats, including wet meadows and dune scrub. Agriculture is a desired use in this region, but the use of fertilizers, pesticides, and herbicides on sandy soils can damage water quality and grazing animals have the potential to increase soil erosion and sedimentation of streams. Moreover, overgrazing is a serious threat to the native flora and fauna, especially the rare Pacific sand bear scarab beetle (Lichnanthe ursina) and the rare plant, Pt. Reyes bird's beak (Cordylanthus maritimus ssp. palustris). In the early1990s, another endangered plant species, Tidestrom's lupine (Lupinus tidestromii), disappeared from Lawson's Landing due to overgrazing.
The sand quarry at Lawson's Landing has been in operation since 1976. Every year 60,000 tons of sand are taken from the dunes for use in concrete, dairy barns, gardens, and golf courses. In 1990, Marin County issued a permit for expansion of the operation from 23 to 39 acres without requiring the preparation of an environmental impact report. The rationale for enlarging the quarry area was to create two quarry sites that could be alternated, in order to allow the sand to be replenished by wind deposition. But the foredunes are now largely overrun by European beachgrass, which traps all onshore-blown sand, so the mined dune is no longer a renewable resource, but one of finite proportions.
There are three quarry sites: one is abandoned; a second has not been worked since 1991 but may be brought back into action in the future, and the third is still active. Wooly headed-spineflower (Chorizanthe cuspidata var. villosa), considered as endangered by the California Department of Fish & Game, grows at two of the three sites. The Pacific sand bear scarab beetle, which was previously found in the quarry area, has not been recorded there since 1998.
Despite a requirement by the County, no reclamation work has been done at the abandoned quarry, which is now more than half covered with European beach grass and iceplant. Consultants hired by the quarry owners state that "any attempts now to rid the quarry of this species (European beachgrass) would probably be futile." European beach grass has overrun more than one-quarter of the second site and, according to the consultants, "is slowly encroaching upon the open sand and native vegetation."
The spread of European beachgrass is a particular hazard for western snowy plovers, a threatened species that nests on sand. Snowy plovers need the low, sparse vegetation that native grasses provide; they will not nest in beachgrass, which grows high and dense and provides excellent cover for predators. Point Reyes National Seashore is spending hundreds of thousands of dollars on a model beachgrass eradication program. But the expensive effort could be undermined by the presence nearby of a source of grass that could re-invade the cleared areas.
The most visible activity on Tomales Dunes is recreation, mainly camping, fishing, claming, crabbing, abalone diving, and boating. Historically, most of Lawson's Landing's vacationers come from the Valley and Delta region, seeking relief from sweltering inland summers in the relatively cool but sunny coastal zone. Many come in their own mobile homes and travel trailers. An RV park within the dunes houses 233 RVs, most of which are here year-round, though not permanently occupied. Creation of the RV park required the destruction of a significant area of dune habitat In addition, another 1000 campsites are available for short-term tent and RV camping in the main meadow, a seasonal dune wetland that has been severely degraded by intensive use. There is no limit on the number of day users allowed on the site. In good weather, several thousand people come to Lawson's each day, with a considerable impact on the dunes, wetlands, and bay. The intense human use, especially the perpetual presence of free-ranging dogs, has driven sensitive bird species, including snowy plovers, from the area.
The tidal mudflats off Tomales Dunes are also an important breeding and pupping ground for harbor seals. Clam digging, fishing, and boating are the major causes of disturbance. When harbor seals are disturbed, their breeding rates fall and abandonment of immature pups rises. Harbor seals are more than twice as common here as elsewhere in Point Reyes. As a consequence, reproduction rates of harbor seals off Lawson's Landing are 50% lower and pup mortality is 70% higher than elsewhere in Point Reyes. The Clam Clipper, which takes visitors to prime offshore claming spots has been temporarily suspended because overharvesting has resulted in an alarming drop in the clam population. Visitors can still take their own or rental boats out to the mudflats to clam, however, and Fish and Game wardens report many incidents of illegal harvesting and cases of disturbance.
There is ample evidence that Tomales Dunes is suffering under the current level of use. Among the signs of overuse are the low reproductive rate and high mortality rate among harbor seals; the local extinction of Tidestrom's lupine; the decline and possible disappearance of the Pacific sand bear scarab beetle from the site; the damage to dunes and dune wetlands by RVs and campers; the encroachment of alien vegetation onto the mobile dunes; and the loss of snowy plover nesting sites.
There is, however, much opportunity for restoration work in the Tomales Dunes. In 1998, for example, the U.S. Fish and Wildlife Service recommended that the endangered Myrtle's silverspot butterfly (Speyeria zerene myrtleae) be re-introduced to the Tomales dunes, along with Tidestrom's and several other associated plants. Other rare, threatened, or endangered species that may already exist here, or are good candidates for introduction or re-introduction include California black rail (Laterallus Jamaicensis coturniculus), beach layia (Layia carnosa), Coast marsh milkvetch (Astragalus pycnostachyus var. pycnostachyus), Dune gilia (Gilia capitata ssp. chamissonis), Northern beach glehnia (Glehnia littoralis ssp. leiocarpa), and Sonoma spineflower (Chorizanthe valida). In addition, it is not too late to attack the problem of invasive European beach grass. The per acre cost of eradication is high (as high as $30,000 an acre), so the sooner an eradication program is begun, the more affordable it will be.
MASTER PLAN
The most pressing problem facing Lawson's Landing's owners is the fact
that none of the roughly more than 100 primitive septic systems serving
the RV park are legal or permitted by the County. To meet Marin County
requirements, the owners have submitted a Master Plan that calls for the
installation of a new septic system. The new system would collect
wastewater from the entire site and pump it to a recirculating sand filter
for treatment before sending it to a leachfield. But there
are many problems with this proposal. The septic system (both the sand
filter and the leachfield) would be near the campground in the mobile dunes
where moving sands could bury or expose them. To prevent this, the
plan entails planting to stabilize the dunes, an action that would seriously
damage the integrity and ecological dynamics of the mobile dune system.
An alternative plan is to put the leachfields under one of the seasonal
wetlands. However, this would create a year-round wetland and drive
out species that are adapted to the special conditions of a seasonal wetland.
Another problem is that the percolation rates for dune sands are too fast
to allow for purification by soil bacteria and are well outside the limit
established by both Marin County and Regional Water Quality Control Board
regulations.
The other main features of the Master Plan are two new 100,000 gallon water tanks, new overhead powerlines, a new garage, store, and office facility, a new boat washdown area, two RV dumping stations, and many new restrooms. Approval of the plan would also give the County's imprimatur to existing uses whose environmental impacts have not been thoroughly studied, including the quarrying, ranching, and RV camping. If the Master Plan is approved, Tomales Dunes could be exposed to even more intensive use. The availability of more water, a reliable power supply, more septic capacity, more restrooms, new RV dumps, and a modernized shop, garage, and office-not to mention the need to recoup the cost of those investments-will be a powerful inducement to growth. So far there has been no oversight, no opportunity for public comment, and no environmental review of the dramatic growth that has taken place at Lawson's Landing since it opened to camping in the late 1950s.
In 1992, the California State Department of Housing, which oversees mobile home parks, threatened to shut down Lawson's Landing's RV park because it was operating without a permit. A state operating permit requires a County-issued Use Permit, which in turns requires an approved Master Plan, neither of which Lawson's Landing yet has. Nonetheless, Marin County advised the State that it had no objection to the issuance of an operating permit before the Master Plan and Use Permit received approval. The State did issue an operating permit for 233 RVs, 1000 vehicle-loads of campers per day, and unlimited day use. The public was not notified, there was no public comment process and no environmental impact study. The state simply agreed to the level of use that the owners requested. As a result, the number of camping sites went from 46 to 1000.
The Master Plan is a welcome development because it gives the public a chance to voice our concerns about the future of this vital resource. Unfortunately, Marin County's planning department has examined the Master Plan and has decided that no Environmental Impact Report is required before it can be approved. We believe that an Environmental Impact Report is mandatory under the California Environmental Quality Act. Section 15065 of the act requires an Environmental Impact Report if a project "has the potential to