Contact Information

Texas Parks and Wildlife Department
Wildlife Division
Wildlife Habitat Assessment Program
4200 Smith School Road
Austin, TX 78744

Staff Directory


Wildlife Habitat Assessment Program: Other Important Natural Resources

The resources discussed below may not be explicitly protected by state or federal laws but are considered important, rare, at risk of endangerment, and/or of conservation concern to TPWD. TPWD recommends that potential impacts to these resources be evaluated during project planning and environmental assessment. This is not a comprehensive list of all natural resource concerns that need consideration during assessment, but rather a summary of some of the most common concerns encountered on development projects.

Rare Species

Rare species are those native Texas species considered to be imperiled throughout a significant part of their range. Rare species are not protected by state or federal law. However, TPWD tracks these species on the TPWD Annotated County Lists of Rare Species and in the Texas Natural Diversity Database. TPWD actively promotes their conservation in an effort to prevent future endangerment and need to propose for listing. Identifying the potential for adverse impacts to rare species and taking steps to avoid or minimize them on projects helps to further this goal.

General recommendations for rare species: During project planning and prior to construction, project areas should be surveyed for potential habitat for rare species as described on the TPWD Annotated County Lists of Rare Species. If potential habitat for a rare species is found, construction impacts to these areas should be avoided to the greatest extent practicable. If a rare species is found on a project, TPWD recommends contacting the Wildlife Habitat Assessment Program (WHAB) for additional guidance.

As with protected species, and if applicable, TPWD recommends locating construction easements and staging areas in previously disturbed areas and avoiding impacts to undisturbed native vegetation to the greatest extent possible. Again, avoidance of impacts to natural areas would be the most effective practice overall for conserving existing wildlife resources.

Riparian Areas

Riparian areas contain some of the highest quality natural habitats in Texas. Ground disturbing construction activity may have potential to impact stream bank vegetation and water quality, both of which are critical for sustaining the health of the ecosystem.

General recommendations for riparian areas: Please see the TPWD Guidelines for Construction and Clearing within Riparian Areas for recommendations.

Ecologically Significant Stream Segments

TPWD has identified ecologically significant stream segments (ESSS) throughout the state to assist regional water planning groups in identifying ecologically unique stream segments under Texas Administrative Code Title 31 Section 357.43 and Texas Administrative Code Title 31 Section 358.2. Until approved by the legislature this is not a legal designation. The stream segments are identified through extensive review by TPWD staff and are determined to be ecologically important due to one or more of the following criteria: biological function; hydrologic function; riparian conservation areas; high water quality/exceptional aquatic life/high aesthetic value; or threatened or endangered species/unique communities. Many, but not all of the mussel sanctuaries are located in ESSS. During project planning, consult the WHAB program for current information on the locations of ESSS.

General Recommendations for ESSS: Reasons for designation of each of these waterways as ecologically significant can be found at Ecologically Significant Stream Segments. TPWD recommends that developers consider the reasons for designation and avoid impacting features that make these waterways ecologically unique.

Freshwater Mussel Sanctuaries

Texas Administrative Code Title 31 TAC Section 57.157 designates segments of various waterways in Texas as sanctuaries for freshwater mussels. Mussel sanctuaries protect populations of both rare and commercially valuable species from harvest. Designation of the sanctuaries is based on the most current scientific survey data available about the occurrence of mussel populations. Although this designation protects mussels from harvest only, designated waterways are selected because they support populations of rare and endemic mussel species, or are important for maintaining, repopulating, or allowing recovery of mussels in watersheds where they have been depleted. These sanctuaries manage mussels by providing for repopulation after harvest or other use, or loss due to environmental conditions. During project planning, consult the WHAB program for current information on the locations of mussel sanctuaries and the potential for rare and protected freshwater mussels to occur in other waterways in your project area.

General Recommendations for Mussel Sanctuaries: TPWD recommends that projects that cross or are located in close proximity to a waterway designated as a freshwater mussel sanctuary avoid disturbing the streambed to protect species that reside in the streambed. Water quality should be protected from any project related water pollution, including runoff, erosion and sedimentation. TPWD recommends that waterways be surveyed for rare mussels prior to disturbance. If rare mussels are found and stream disturbance is necessary, please contact the WHAB program regarding the potential for relocation of mussels to an area that would not be affected by construction.

Pollinators, Including Monarch Butterflies

The main threats facing pollinators are habitat loss, degradation, and fragmentation. As land uses like roadways and other rights of way, crops, and non-native landscaping replace native vegetation, pollinators lose the habitat needed for survival. Migratory pollinators like monarch butterflies (Danaus plexippus) face special challenges. Significant declines in the population of migrating monarch butterflies have led to widespread concern about this species and the long-term persistence of the North American monarch migration. Augmenting larval feeding and adult nectaring opportunities is part of an international conservation effort for the monarch.

General Recommendations for Pollinators Including Monarch Butterflies: Revegetation of disturbed project sites should include native plants that support the forage, reproduction, shelter and/or hibernation of pollinators. For disturbed sites within the monarch migration corridor, TPWD recommends revegetation efforts include planting or seeding native milkweed (Asclepias spp) and nectar plants as funding and seed availability allow. Information about monarch biology, migration, and butterfly gardening can be found at Where appropriate and sustainable, TPWD recommends landscaping plans incorporate pollinator gardens.

Conservation Easements

A conservation easement is a legal agreement between a landowner and a land trust or governmental agency that permanently limits uses of the land (including future fragmentation) to protect and conserve the land's natural values such as fertile soils, mature trees, and wildlife habitat. Lands with conservation easements protect existing wildlife habitat from future fragmentation and therefore have greater environmental integrity than comparable lands without conservation easements. Potential fragmentation of wildlife habitat from proposed routing of highways, roads, pipelines, transmission lines, and other projects on properties where conservation agreements serve to protect the state's natural resources now and in the future is of concern to TPWD. More information about the importance of these lands can be found at Texas Land Trust Council Publications.

General Recommendations for Conservation Easements: TPWD recommends properties protected by conservation easements be identified during early project planning and avoided during development of project alternatives. Data sources for the location of these properties include online databases such as the National Conservation Easement Database at and the Protected Areas Data Portal at, although these data sources are incomplete and county records may need to be referenced to determine the location of properties with conservation easements.

Native Vegetation

Construction projects usually require removal of existing vegetation in order to build the project. Developers are encouraged to remove as little existing vegetation as possible and use locally adapted native plants in revegetation and landscaping to help preserve native plant communities. Additional information can be found in the TPWD Guidelines for Revegetation of Disturbed Landscapes.

Invasive species pose a significant threat to the existence of native plant communities in areas disturbed by construction. Lists of invasive species can be accessed online at

General recommendations for vegetation removal and revegetation: When assessing potential impacts to vegetation on a project, current aerial imagery should be reviewed. The project area should be ground-truthed in conjunction with the Texas Ecological Systems Classification Project or the Vegetation Types of Texas to determine if the mapped plant communities still exist in the project area. If not, the current, existing vegetation community should be documented.
For projects that incorporate revegetation or landscaping, the TPWD Texas Wildscapes website has information about selecting native plants that would be best suited for the particular project area. An additional resource is the Lady Bird Johnson Wildflower Center's Recommended Native Plants Database.
In accordance with the Executive Order on Invasive Species (EO 13112) and the Executive Memorandum on Beneficial Landscaping (which apply to projects with a federal nexus), TPWD recommends that practices be implemented to prevent the establishment of invasive species and sustain native species, particularly during the early stages of revegetation. Native alternatives to invasive plant species are available through the Texas Invasives Database.