Water Obstruction & Encroachments for Streams, Wetlands, and Floodways



Pennsylvania has over 86,000 miles of streams and rivers which drain its over 46,000 square miles. There are regulations, known as Chapter 105, Dam Safety and Waterway Management, that were created to protect the health, safety, welfare and property of the people; and to protect natural resources, water quality and the carrying capacity of watercourses.

These regulations are administered by the Pennsylvania Department of Environmental Protection (DEP). For Huntingdon County, all Chapter 105 permitting should be submitted directly to DEP. Our District staff can help to provide basic permitting information in advance for your projects, but we are not delegated to administer any portion of the Chapter 105 Program. For technical assistance, please call the PA DEP South-central regional office's Waterways & Wetlands Program (Harrisburg) at (717) 705-4802 and ask for the 105 Permitting Engineer assigned to Huntingdon County. 


Do I need a permit?

The Guidelines for Maintaining Streams in Your Community booklet and more resources for landowners can be found by visiting the Flooding and Maintenance of Pennsylvania’s Streams website .

Activities and structures in or near a stream or its adjacent floodway are regulated by the Chapter 105 program. In most cases, a permit is required before starting any activity which changes, expands or diminishes the course, current or cross-section of a stream, floodway or body of water. This means that most types of excavation in, along, or across a stream- even if the excavated material is put back after the work, will usually require some kind of Chapter 105 permit or authorization.


So, what exactly are Regulated Waters?

Regulated waters of this Commonwealth include any watercourses, streams, or bodies of water (ponds, lakes, and wetlands) and their floodways.

A regulated stream includes any channel or conveyance of surface water having defined bed and banks, whether natural or man-made, perennial, or intermittent. Keep in mind, many streams do dry up in the summer months, however, the definition does include those streams as well.

A floodway includes the channel of the stream and portions of the adjoining floodplain necessary to carry and discharge the 100 year frequency flood. Some municipalities have flood insurance studies and maps prepared by the Federal Emergency Management Agency (FEMA) which indicate the floodway boundary for major rivers and some streams. In the absence of such a study, the floodway is considered to extend from the stream to 50 feet from the top of each streambank.

For any proposed activity or structure located on a floodplain, first, check with the FEMA Floodmap Service Center

FEMA delineated floodways are illustrated as those areas with the pink and blue stripes and labeled Regulatory Floodway under Special Flood Hazard Areas. If your project falls outside of the FEMA delineated floodway areas, then it is assumed, absent evidence to the contrary, that the regulated floodway extends to 50 feet from the top of the bank of the stream. A permit is required for any excavation, placement of fill material, or structure, whether temporary or permanent, located in a floodway.


Do you know that not all wetlands have cattails?

Wetlands are areas where water covers soil, or is present at or near the surface, all year or part of the time during the growing season. Wetlands are important because they protect and improve water quality, provide fish and wildlife habitats, store floodwaters and maintain surface water flow during dry periods. Pennsylvania has over 400,000 acres of wetlands. These include forested wetlands, scrub-shrub wetlands, and emergent wetlands. Water saturation (hydrology) largely determines how the soil develops and the types of plant and animal communities that are supported. The prolonged presence of water creates conditions that favor the growth of specially adapted plants (hydrophytic) and promote the development of characteristic wetland (hydric) soils.

During project planning it may be necessary to conduct a wetland determination and/or delineation if the area for earth disturbance contains wetland indicators such as hydric soils or hydrophytic vegetation. Please review the following guides and consult with a person trained in wetlands; our office can provide a list of available consultants in the area. A permit is required for any direct impacts to wetlands including earth disturbance activities, placement of fill, or structures, whether temporary or permanent.

An Introduction to Wetlands

Clues to Wetland Identification

List of Hydric Soils in Huntingdon County

Types of Chapter 105 Permits

Chapter 105 General Permits were created for activities or structures that do not pose a significant threat to flooding or the environment. A Chapter 105 General Permit (GP) has a pre-approved set of conditions, construction limits, dimensions and other criteria which apply to many common types of projects. If the work that an applicant is proposing meets all of the conditions of the GP, then the applicant need only register his/her intent to use said GP, and receive acknowledgement or authorization from DEP. The conditions of each GP are included in Part One and Part Two of the permit package.

PA DEP Waterways Engineering and Wetlands e-Library Chapter 105 General Permits

These permits are issued by the DEP South Central Regional Office. Once the permit application is submitted to DEP, please allow for approximately 3-5 months of wait time to receive the permit authorization. If a permit is required, construction may not begin until authorized by DEP.

The following is a list of GENERAL PERMITS:


Certain activities and structures may qualify for a Chapter 105 permit waiver. The complete list of waivers is located under  DEP’s Chapter 105 Rules and Regulations. 105.12 Permit Waivers

How to Calculate the Stream Drainage Area (PDF)

If your water obstruction and encroachment activity does not meet the conditions of a General Permit or a specific 105.12 waiver, then a Water Obstruction and Encroachment USACOE Section 404 Joint Permit and/or an Environmental Assessment is likely required.


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Do ponds require permits?

If you want to build a dam or pond, but you are not sure if you need a permit, the District can help with understanding the permitting requirements for a proposed new pond or maintenance of an existing pond. First, you need to determine whether the pond would be considered as jurisdictional or non-jurisdictional for dam permit authorizations. Click here to find out more information and view the DEP Fact Sheet for Dam Permits in Pennsylvania (PDF).

If the proposed dam is non-jurisdictional, but is located in, along or projecting into a wetland or across a stream, DEP approval of an Environmental Assessment is required. In addition, any excavation of wetlands, stream or floodway within the impoundment area would require an encroachment permit from DEP, as described above.

Section 105.15 Environmental Assessment Approval to Construct a Non-Jurisdictional Dam

If the pond is to be located off-stream, will there be an inlet from a stream to the pond and/or an outfall from the pond to a stream? A GP-4 General Permit is required for any inlet and outfall structures, however, may not be used in a High Quality or Exceptional Value waterways.

For more information, check out the Penn State Extension articles Pond Agencies and Permits in Pennsylvania and Resources for Pond and Lake Owners

It is always advisable to reach out to the District prior to conducting any earth disturbance activities, especially when working near a stream or wetland. A written E&S plan is required for ALL Chapter 105 permitting and must be approved by the Conservation District prior to construction (with the exception of the GP-11 which is submitted directly to DEP).

Chapter 105 Permitting Resources