Human &
Ecological Values

  • Provided by Marshland
  • Flood control
  • Storm abatement
  • Water quality improvement
  • Aquifer recharge
  • Aesthetics
  • Recreation
  • Waterfowl and other bird habitat
  • Fish and shellfish habitat
  • Endangered/threatened species habitat

Representative Rare or Endangered Species in Suisun Marsh


  • Salt marsh harvest mouse
  • Salt marsh wandering shrew
  • Suisun ornate shrew


  • California black rail
  • California clapper rail
  • Suisun song sparrow
  • Reptiles
  • Northwestern pond turtle


  • Delta smelt
  • Longfin smelt
  • Sacramento splittail
  • Spring/Winter-run Chinook salmon


  • Delta tule-pea
  • Hispid bird-beak
  • Mason’s lilaeopsis
  • Soft bird’s beak
  • Suisun Marsh aster
  • Suisun thistle

Grayhawk At Suisun Marsh:
An Ecologically Senstive Residential Community

Grayhawk at Suisun Marsh is located at the boundary of the largest contiguous brackish water marsh remaining on the west coast of North America. In geography, a marsh is a type of wetland, featuring grasses, rushes, reeds, sedges, cattails, and other herbaceous plants (possibly with low-growing woody plants) growing on soft, wet and low-lying land near shallow water. Technically, a marsh is different from a swamp, which is dominated by trees rather than grasses and low herbs. The shallow water near marshes can be fresh, saline or, as in the case of Suisun Marsh, brackish. What was once considered by land developers during the earlier part of the last century as a nuisance, mosquito-infested waste land is now valued as an important and critical part of the San Francisco Bay-Delta estuary system.

Why then are marshes such as Suisun Marsh now considered so valuable? Primarily, these areas have demonstrated value because of the physical, biological, and economic functions that they provide, which are useful to humans and the environment. Marshes do not just do one thing. Scientists are in agreement that marshes, such as Suisun Marsh, perform many processes simultaneously and therefore provide a suite of values to humans and the environment:

What Is So Unique About Suisun Marsh?
Encompassing 116,000 acres, the Suisun Marsh includes 52,000 acres of managed wetlands, 27,700 acres of upland grasses, 6,300 acres of tidal wetlands, and 30,000 acres of bays & sloughs. It is home to public waterfowl hunting areas and 158 private duck clubs. In addition, the Marsh provides essential habitat for more than 221 bird species, 45 mammal species, 16 different reptilian and amphibian species, and more than 40 fish species. Some of these animals, in addition to plants, are considered by the State of California and the United States as rare or endangered.

The Marsh also supports 80% of the state's commercial salmon fishery by providing important tidal rearing areas for juvenile fish, allowing them to grow twice as fast as those reared in the upper watershed, thus, greatly enhancing their survival.  To further enhance the lives of people living in the region, 230 miles off levees within the Marsh provide critical protection of the drinking water for 22 million people by preventing salt water intrusion into the Delta. The Marsh's large open space and proximity to vast urban areas also makes it ideally suited for wildlife viewing, hiking, canoeing, and other recreation opportunities.

Living Near Suisun Marsh

Suisun Marsh is not a static, ecological system. There are subtle and not so subtle changes that occur seasonally within the marsh, all of which contribute to the beauty, natural resource diversity, and unique character of the area with seasonal changes. Most of the Marsh itself is a seasonal brackish wetland that often is dry during the summer, coming back to lushness during the winter rainy season.

The Marsh encompasses more than 10% of California's remaining natural wetlands and serves as the resting and feeding ground for thousands of waterfowl migrating seasonally on the Pacific Flyway, a major north-south migration route. In fact, the greater portion of Suisun Marsh is managed as waterfowl habitat, and only 10 square miles is left in its original state. Fortunately, a tenth of this natural area lies within the Rush Ranch Preserve, an area that is within a few miles of Grayhawk at Suisun Marsh. Rush Ranch protects one of the few remnants of estuarine marsh in the Bay Area.

Suisun Marsh slowly yields its beauty to those fortunate enough to live near this regionally important ecological resource, but living in the area also creates an awareness of both the natural processes in a wetland environment as well as man-induced management required to sustain the system as waterfowl habitat, while being sensitive to surrounding urban development. For example, just by the nature of a brackish water system defined by seasonally wet sloughs and channels, make such naturally occurring, but nuisance annoying, mosquitoes an inevitable consequence of living near a wetland. The nuisance, however, is reduced in Suisun Marsh through mosquito abatement, relying primarily on biological and physical control methods. The Solano County Mosquito Abatement District controls mosquitoes through: (1) water manipulation/management, (2) vegetation management, and (3) mosquito predators, such as fish and invertebrates. Marsh vegetation management may include discing, mowing or burning. Occasionally, burning is required and smoke may be visible over the Marsh. If such burning is required, however, it is administered by the Bay Area Air Quality Management District, according to specific daily Burn/No Burn periods during the spring to protect air quality and the health of those living near the Marsh.

Stewardship And Protection

Grayhawk at Suisun Marsh recognizes the importance Suisun Marsh and that is why the development has incorporated such physical protective features as fencing, restricting domestic pets from encroaching into the marsh. The primary goal of this physical barrier is to protect and preserve the marsh’s wildlife habitat values. There are additional actions that homeowners can take to enhance this protection and to guarantee the preservation of the Suisun March’s intrinsic beauty, its water quality and its unique wildlife and plant resources. It is extremely important that all residents of Grayhawk are aware of some “Do’s and Don’ts” that should guide our living near such a valuable resource as Suisun Marsh.

Grayhawk at Suisun Marsh
Wetland Protection Do’s and Don’ts
Install energy-efficient, fully-shielded lighting fixtures outdoors to reduce glare by directing light downward, controlling nighttime lighting to the marsh. Don’t create “light pollution” into Suisun Marsh.
Install native plants in yards facing the marsh to prevent invasion of non-native, aggressive plant competitors to the marsh. Don’t use Pampas grass, English ivy, periwinkle and other plants listed by the California Exotic Pest Plant Council (CalEPPC) in landscaping yards abutting Suisun Marsh.
Clean up after your pets. Pet waste contains nutrients and pathogens that can contaminate surface water. Don’t let pet feces accumulate near the fence line barrier to Suisun Marsh.
Prevent the discharge of pesticides and herbicides from going directly into the marsh.
Don’t use excessive amounts of herbicides and pesticides in gardens or lawns.
Use fertilizers sparingly. Do not apply pesticides or fertilizers before or during rain due to the strong likelihood of runoff to areas that might drain into Suisun Marsh.
Protect waterfowl Don’t feed waterfowl.

Often when we think of biodiversity, we envision the lush tropical rainforests of South America, the grassy plains of Africa, or the coral reefs of Australia.  But there is a place close to home that provides a rich diversity of plants and animals that is within easy distance from Grayhawk at Suisun Marsh.  Be aware of its beauty, its ecological importance, and our responsibilities to serve as proper stewards to protect this value resource
Suisun Marsh.

GrayHawk at Suisun Marsh is developed by Harbor Park, LLC
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