Wildlife and Habitat

The Endangered Species Act applies to both public and private actions that will likely jeopardize the continued existence of endangered or threatened biological species or destroy critical habitat for such endangered or threatened species. The U.S. Fish and Wildlife Service and the National Oceanic and Atmospheric Administration (fisheries) share responsibilities in administering this legislation.

Several key definitions used in the analysis of wildlife and habitat, per various Sections of Title 50 Code of Federal Regulation, are listed below.

Action Area

Action areas refer to “all areas to be affected directly or indirectly by an action and not merely the immediate area involved in the action.” This is very critical as an action area could be outside of a project (right of way) limit.

Incidental Take

An Incidental Take is the “take of listed fish or wildlife species that results from, but is not the purpose of, carrying out an otherwise lawful activity conducted by a federal agency or applicant, or contractors working on behalf of the applicant.” During the impact analysis process, early consultation with the U.S. Fish and Wildlife Service ensures an alternatives viability. Additionally, subject matter experts at the Federal and state environmental resource agencies can help to discover issues early on and offer options for highway engineers to consider in order to avoid and minimize impacts.

Floodplains, Stormwater Runoff, and Water Quality

Executive Order 11988, Floodplain Management requires that the construction of all federal and federal-aid facilities, including buildings, roads, and physical objects encroaching upon base floodplain (100-year floodplain), needs to consider alternatives to avoid direct and indirect take of floodplain areas.

U.S. DOT Order 5650.2 Floodplain Management and Protection and Federal- Aid Policy Guide 23 CFR 650A outlines specific criteria and approaches in dealing with floodplain issues.

Per 23 CFR 650A, “It is the policy of the FHWA:

a. To encourage a broad and unified effort to prevent uneconomic, hazardous or incompatible use and development of the nation’s floodplains.

b. To avoid longitudinal encroachment, where practicable.

c. To avoid significant encroachments where practicable.

d. To minimize impacts from highway agency actions that adversely affect base floodplains.

e. To restore and preserve the natural and beneficial floodplain values that are adversely impacted by highway agency actions.

f. To avoid the support of incompatible floodplain development.

g. To be consistent with the intent of the Standards and Criteria of the National Flood Insurance Program, where appropriate.

h. To incorporate A Unified National Program for Floodplain Management’ of the Water Resources Council into the FHWA procedures.”

The intent of these laws and regulations is to avoid and minimize encroachment from highways and highway-supported land development that reduces stormwater storage capacity and increases water surface elevations within 100-year floodplains.

Stormwater Runoff Quantity (Flooding) Control

Pavement surfaces are impervious. Rain or other precipitation falling on a road will not be able to permeate to the underlying soil. Instead, the water runs off the

a Stormwater detention pond illustration

Figure 5.4a Stormwater detention pond illustration.

pavement surface in greater quantity (due to a lack of vegetation interception and soil adsorption) with faster speed (roadway cross scope to keep the traveled way dry) than it would under the natural condition. This phenomenon may cause flooding of adjacent properties (Figure 5.4a).

To maintain the natural stormwater drainage pattern and prevent flooding, runoff is channeled into stormwater retention or detention ponds first. From there, discharging the runoff is controlled at a rate not to exceed its “natural state” rate. The “natural state rate,” also called “pre” rate refers to the runoff rate in the absence of any roadway facility. The guiding principle is that the post-discharge rate (with the presence of a roadway system) shall not exceed the natural state pre-discharge rate.

Stormwater pond sizing, channeling, and discharge facilities are designed by drainage engineers (hydrology).

Stormwater Water Quality Control Construction Activity Related

The CWA prohibits discharging pollutants through a point source into the “water of the United States” unless the discharge is permitted under a National Pollutant Discharge Elimination System (NPDES) permit.

The NPDES program is managed by the U.S. EPA and is often delegated to State environmental resource regulatory agencies for permit administration. The Stormwater NPDES program applies to all outdoor construction activities. This includes land clearing, soil grading, and soil excavating in areas of soil stockpiling, soil borrowing, material storage, and equipment storage. Highway construction falls within these specified activities.

A construction activity owner (an activity owner - e.g., a contractor), not the project owner (e.g., a state DOT), is generally responsible for obtaining the NPDES permit from a state’s environmental regulatory agency. A permit represents written permission from a regulatory agency allowing a construction company to conduct fieldwork under the condition outlined in the permit. Construction companies comply with all permitting conditions by developing and implementing stormwater pollution prevention plans as outlined below.

  • 1. Identifying potential sources of stormwater pollutants including sediment, oil, and grease from storage and spill, trash, sanitary and septic, and others.
  • 2. Identifying and implementing good practices, including isolation and filtration, and good housekeeping conservation techniques to prevent pollution.
  • 3- Installing erosion control material, monitoring compliance, reporting and remediating violations.
  • Operations Related

Once a road opens to traffic, a wide range of contaminants ranging from leaked engine oil, vehicle and cargo spills, dust and particles from tire wear and tear, dust from brake wear, to debris from roadway surface deterioration accumulate on the roadway surface. When precipitation falls on a road, these accumulated materials are washed away, potentially polluting receiving water bodies (Figure 5-4b).

To protect receiving water quality, stormwater runoff from a road is required to be retained for a certain amount of time before it can be discharged into lakes, rivers, or any other aquifer. This retention enables the settlement of various suspended

b Illustration of leaked oil on roadway surface

Figure 5.4b Illustration of leaked oil on roadway surface.

particulate materials. Stormwater retention ponds are designed to meet both water quantity (flood) and water quality needs.


  • • potential flooding of adjacent properties and
  • • polluting receiving waterbodies.


The Farmland Protection Policy Act (FPPA) is created to minimize, through projects and programs permitted or funded by the Federal government, the conversion of farmland to a nonagricultural use. The FPPA protection applies to farmlands even if such lands are not in active use as cropland. FPPA lands can be forest land, pastureland, cropland, or any other lands, as long as they are not water or urban built-up land.

The Natural Resources Conservation Service (NRCS) of the U.S. Department of Agriculture is responsible for ensuring that FPPA is implemented.

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