Section 2: Natural Resource Surveys
Anchor: #i1003715Overview
This section covers processes and guidelines for performing natural resource surveys. Natural resource surveys gather information and assess potential impact on plant and animal species and their habitat, and water and water related natural resources, such as wetlands. It is important that data collection efforts be consistent with the level of impacts to be evaluated for a particular project and that the methods used are selected to assure that the collected data will answer the appropriate questions. ENV's Natural Resource Management (NRM) staff is available to assist districts with this type of information.
Anchor: #i1003730Natural Resource Survey Activities
- Describe scope of impact
- gather and assess natural resource data, including threatened/endangered species
- determine Coastal Barrier Resource Act applicability
- determine wetland status and needs
- determine permit needs.
Scope of Impact
The natural resource data in an environmental document must be sufficient to determine whether the impacts of the projects are significant and within the scope of NEPA. Every action that TxDOT takes must be evaluated for potential effects on biological and water resources.
When adequate information to describe project impacts cannot be located from sources such as those listed below, it may be necessary to develop original site specific information through field inventory or research. A qualified biologist can collect original biological data.
Anchor: #i1003779Natural Resource Data
The information needed to describe the natural resources of a project location may include, but is not limited to:
- land use and disturbance history for the existing and new ROW and adjacent lands
- project design information
- topographic information
- geology and soils information
- water resources information
- regional and project area vegetation information, including dominant species, size range of dominant trees, percent canopy coverage, height and trunk size, native, introduced or mixed grasses (for grasslands)
- special habitat features, such as streams, lakes, cliffs
- animal species occurrences, especially any occurrences documented for the site (long species lists do not help), and any animal species density information that may be available for the location
- occurrences of species of special concern, such as federal threatened and endangered species which occur in the project area
- any other information required to complete a standard
habitat evaluation such as habitat evaluation procedures (HEP -
USFWS) or wildlife habitat appraisal procedures (WHAP - TPWD). If
a standard procedure such as HEP or WHAP is used to evaluate habitat,
the changes that a project causes to habitat can be quantified as
a numerical rating.
NOTE: Projects that do not include new habitat disturbance or small amounts (less than one acre) of new resource disturbance may be adequately described with abbreviated habitat descriptions unless there are special considerations for the area, such as the potential occurrence of a listed threatened or endangered species.
Information Sources:
- biological conservation database (BCD)
- field observation
- USGS topographic maps
- aerial photographs
- county soil survey reports
- National Wetland Inventory maps
- TPWD publications/personnel
- published research reports for the area (public libraries)
- USFWS lists of threatened and endangered species
- local universities
- local subject matter experts and outdoor clubs (Audubon, etc.)
- Bureau of Economic Geology (at the University of Texas at Austin's J.J. Pickle Research Center).
Community Participation in National Flood Insurance Program
Determining the status of a community’s participation in the National Flood Insurance Program (NFIP) and review of applicable NFIP maps and ordinances are essential first steps in preparing environmental documents and conducting location hydraulic studies.
Information of community participation in NFIP is provided in the National Flood Insurance Program Status of Participating Counties, published semi-annually for each state and available through the headquarters of the Federal Emergency Management Agency (FEMA) or the Texas Natural Resource Conservation Commission/Texas Commission on Environmental Quality (TNRCC/TCEQ). Contact ENV for addresses.
Anchor: #i1003935Applicable NFIP Maps
If a highway project encroaches on the base floodplain within a community participating in NFIP, the local government floodplain administrator with land use jurisdiction should be notified.
Communities in the regular program of NFIP generally have had detailed flood insurance studies performed. In these communities, the NFIP map will be an insurance rate map and in the majority of cases, a regulatory floodway is in effect.
Communities in the emergency program of NFIP usually have not had a detailed flood insurance study completed and, usually, only limited floodplain data is available. In this case the community NFIP map will be a hazard boundary map and there will not be a regulatory floodway.
Anchor: #i1003955Coastal Barrier Resources Act (CBRA) Applicability
The Coastal Barrier Resources Act (CBRA) outlines requirements to minimize the loss of life, the wasteful expenditures of federal money, and damage to the natural and other resources of coastal barrier systems along the Atlantic and Gulf coasts. Each TxDOT coastal district has maps on file identifying areas applicable to CBRA.
Anchor: #i1003965Wetland Impacts
What is a wetland? Wetlands are those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support (and that under normal circumstances do support) vegetation typically adapted for life in saturated soil conditions. Under normal circumstances, a wetland contains water, hydric soils, and wetland vegetation.
TxDOT's construction and maintenance of transportation facilities frequently involves encroachments into waters of the U.S.; therefore, TxDOT must determine whether a proposed activity will take place within navigable waters, jurisdictional waters, or wetlands, and whether the activity will destroy or degrade waters of the U.S., including wetlands. To make this determination, the following information is required:
- proposed construction methods resulting in impact
- design factors for consideration of final alignment
- approximate impacts to waters of the U.S., including wetlands in acres and cubic yards.
Wetland Status and Needs
A wetland survey is used to determine the location and extent of the wetland(s), and draw conclusions about the type of wetland and its probable function(s) and, perhaps, its value. Preliminary data gathering prior to the site visit provides much needed baseline information on the area of interest.
Available data pertinent to wetland determination may include the following items:
- field survey
- NRCS soil survey for county
- a list of hydric soils mapped for the area
- Black and white or color infrared (CIR) aerial photographs, one of the most useful tools for conducting a wetland evaluation. Color infrared photography is the most desirable because land use, vegetation, and communities can be determined. In some cases, wetlands can be determined from color infrared with ground truthing of signature sites.
- USGS 7.5-minute topographic quadrangle map
- any additional topographic details
- USFWS National Wetlands Inventory (NWI) maps - these maps offer a broad look at potential wetland sites and types and generally use the 7.5 minute quadrangle as the base map. It is important to remember that this cannot be used in lieu of the wetland delineation.
- USFWS National List of Plant Species that Occur in Wetlands - this list provides the indicator status of plants often found in wetlands and is required in order to complete wetland delineation forms
- The 1987 U.S. Army Corps of Engineers (USACE) Manual - the manual offers step-by-step procedures for wetland delineation. The manual standardizes these procedures and the data sheets for the sample points so that wetland delineators can be consistent in their individual determinations.
Proposed Construction Methods
The construction method that will be deployed for a project is key to determining compliance. For example, the environmental impacts caused by the removal of a bridge hinges upon the method by which it is removed. It is important to make the distinction as to what parts of the project will have temporary impacts and what part of the projects will have permanent impacts to the resource.
Anchor: #i1004084Design Factors
Project design factors give an indication early in the process as to whether projects can be designed to avoid or minimize impacts to jurisdictional areas. The extent of impacts to jurisdictional areas will have direct bearing on the extent of coordination and mitigation that may be required.
An understanding of project requirements in light of the location and extent of jurisdictional areas could therefore make a considerable difference in the time and money that will be invested in the remainder of the project development process.