Check Dam

Check dams are used to reduce gullying in the bottom of small channels or drainage ways and serve to reduce the velocity of flow by ponding runoff in the channel.  Check dams are usually made of stone, with smaller stones used on the upslope side.  The center section must be lower than the edges, spaced so that the toe of the upstream dam is at the same elevation as the top of the downstream dam.

Properly installed check dams

Failed check dam

Construction Entrance/Exit

The purpose of a temporary construction entrance/exit is to provide a buffer area where vehicles can drop their mud and sediment to avoid transporting it onto public roads, to control erosion from surface runoff, and to help control dust.  This practice applies wherever traffic will be leaving a construction site and moving directly onto a public road or other paved off-site area.

This is an excellent construction entrance. No mud is entering the roadway.

This construction entrance is failing. It has no rock or fabric to keep mud from entering the road.

Curb Inlet Filter

Curb inlet filters are applicable at curb inlets where an overflow capability is necessary to prevent excessive ponding in front of the structure.  Gravel filters are placed in a U-shape around the stormdrain in an attempt to keep sediment out.

Properly installed curb inlet filter

Failed curb inlet filter

Ground Cover

Permanent seeding of grasses and legumes is the most common and economical means of establishing protective cover.  Vegetation controls erosion by physically protecting a bare soil surface from raindrop impact, flowing water, and wind, as well as binding soil particles together with a dense root system.  Seeding should be covered with mulch during the growing process, especially on slopes, and should be anchored down with netting.  Vegetation is the preferred method of surface stabilization wherever site conditions permit.

This is good, healthy ground cover

This ground cover is failing

Inlet Protection

There are numerous types of inlet protection measures, including hardware cloth and gravel inlet, an excavated drop inlet, block and gravel inlet, sod drop inlet, rock doughnut inlet, and rock pipe inlet.  All measures are used so that storm drain systems can be used during construction, but sediment is prevented from entering them.  Which inlet protection measure is used depends in part on what rate of flow is anticipated going into the drain.

This is a good example of proper inlet protection

This inlet is clearly failing

Mulching

The application of a protective blanket of straw or other plant residue, gravel, or synthetic material to soil surfaces protects the soil from the forces of raindrop impact and overland flow.  Mulch fosters the growth of vegetation, reduces evaporation, insulates the soil, and suppresses weed growth.  Netting, mats, or other anchoring mechanisms should be applied to hold the mulch in place.

This mulch is thick enough to work properly

This mulch is too thin. You can see dirt through the mulch and it's washing away at the top of the slope.

Outlet Protection

Outlet protection is a structure designed to control erosion at the outlet of a channel or conduit by reducing the velocity of flow and dissipating energy.  A riprap-lined apron is the most commonly used structure for this purpose because it has a relatively low cost and can be installed easily on most sites.  A filter consisting of a graded gravel layer or a synthetic filter cloth should be installed under the riprap to prevent soil movement through the openings between stones.

Proper Outlet Protection

Failing Outlet Protection

Sediment Basin

Sediment basins are located to trap sediment near the outlet of a work site and should be installed before clearing and grading begin.  The basin should contain a spillway outlet and the embankment should be well compacted and vegetated.  Baffles made from a porous material should be installed, as well as a riser and barrel with a skimmer attached.

This sediment basin is working properly

This sediment basin needs maintenance

Silt Fence

A silt fence reduces the velocity of flow, allows deposition, and retains sediment.  Fences should not be installed across streams or ditches, or where flows are concentrated.  They are constructed of a permeable barrier erected on a small disturbed area and the fabric is buried at the bottom, stretched and supported by steel posts.  Silt fences may be designed to store all the runoff from a site, or located to allow bypass flow when the temporary sediment trap reaches a predetermined level.

Properly installed silt fence

Failing silt fence

Temporary Sediment Trap

A temporary sediment trap is usually formed by constructing an earthen embankment across a low area to form a sedimentation pool during rainfall runoff events.  An outlet spillway section constructed of stone provides drainage for the trap and three porous baffles should be installed to maximize trapping efficiency.  The sediment trap should be surrounded by vegetation.

This is an excellent temporary sediment trap

This temporary sediment trap is clearly overwhelmed and failing

NC Local Program Contacts

In North Carolina, there are 50 local erosion & sediment control programs that have been delegated the authority to enforce the NC Sedimentation Pollution Control Act and to oversee construction site activity within their jurisdiction.  If you live in a city, town, or county that has a local program, you should first contact someone from that program with concerns about sedimentation violations.  If the area you live in does not have a local program, contact the appropriate regional office of the Division of Land Resources to figure out who you should call.

Online Training Workshops

The purpose of the online training workshops is to provide MWW volunteers an opportunity to make-up a missed workshop.  In addition, the online lessons are perfect for reference and review.  

Please note, the workshops are designed to provide a general overview of the MWW workshop material.  They are used by all volunteers and therefore will not follow any particular Riverkeeper lesson plan.  If you are making up a class, choose the topic or topics that cover the material you missed.

Erosion and Sediment BMP's

This is the largest of the four online workshops.  To simplify the process, this workshop has been separated into five modules.  Work at your own pace, begin with Module 1 and end with Module 5. 

*Each module contains many photos; it may take a few minutes to open the PDF's.  

*Please have the laminated Erosion and Sediment Control Pictorial Field Guide provided in the MWW Workbook nearby for reference.

Module 1: Erosion Control Fencing

Module 2: Check Dams

Module 3: Inlets and Outlets

Module 4: Sediment Ponds

Module 5: Ground Covers

 

Resource Uploads: 

erosion_control_fencing_session_1.pdf

check_dams_session_2.pdf

inlets_and_outlets_session_3.pdf

Permitting and Regulations

This online workshop provides a brief overview of permiting and regulations as they pertain to erosion and sediementation controls on construction sites on North Carolina. Please have your MWW workbook handy, you will be reviewing material behind the index tab titled "Understanding Permits."

Understanding Permits

 

Resource Uploads: 

understanding_permits.pdf

Visiting a Construction Site

This online workshop was designed to help the MWW volunteer prepare for their first visit to a construction site. To complete the lesson, you should review the section titled "Evaluating a Site" in the MWW workbook. We highly recommend watching the DVD titled, "A brief History of Permit Non-Compliance," narrated by Drew Koslow. This DVD should be included with your MWW workbook. If not, please ask your Riverkeeper for a copy of the DVD.

MWW Site Visit

Resource Uploads: 

mww_site_visit_3.pdf

Resource Links

North Carolina Division of Land Resources Regional Office Erosion and Sediment Control Programs
http://www.dlr.enr.state.nc.us/pages/sedimentlocalprograms.html
Click on Local Program Contact Information

North Carolina Sedimentation Control Commission meeting agendas
http://www.dlr.enr.state.nc.us/scc.html

From this site http://www.dlr.enr.state.nc.us/pages/links.htm the following information can be found:

Erosion and Sedimentation Control

Stream Classification
• North Carolina Division of Water Quality - Environmental Sensitivity Maps by County
• North Carolina Division of Water Quality - North Carolina Water bodies Reports

Precipitation Data
• NOAA's National Weather Service Hydrometeorological Design Studies Center
• NOAA's Precipitation Frequency Data Server

Erosion and Sedimentation Control - Associations
• American Academy of Environmental Engineers
• American Society of Civil Engineers
• CPESC, Inc.
• International Erosion Control Association
• Institute of Professional Environmental Practice
• National Association of Environmental Managers
• National Association of Environmental Professionals
• North Carolina Board of Examiners for Engineers and Land Surveyors
• National Association of Soil and Water Conservation Districts
• Soil Science Society of America
• Soil and Water Conservation Society

Erosion and Sediment Control - Other resources
• American Society of Civil Engineers - Storm water best management practices
• Land Surveyor Reference Page
• National Society of Consulting Soil Scientists, Inc. (NCSS) -  soil science links
• North Carolina County Geographic Information System (GIS) data - see especially RAMONA
• North Carolina State University - BAE Storm water Engineering Group
• North Carolina State University - Department of Soil Science
• State Climate Office of North Carolina - Primary source for North Carolina weather and climate information
• Storm water (North Carolina State University)
• Water Resources Research Institute (WRII) of The University of North Carolina

Low Impact Development
Low Impact Development is a comprehensive land planning and engineering design approach with a goal of maintaining and enhancing the pre-development hydrologic regime of urban and developing watersheds.

www.lid-stormwater.net

www.lowimpactdevelopment.org

www.epa.gov/owow/nps/lid/stormwater_hq/

Stormwater
The North Carolina Division of Water Quality Stormwater Permitting Unit currently administers the state stormwater management program and the federal NPDES stormwater management program.  http://h2o.enr.state.nc.us/su/index.htm

The North Carolina Stormwater BMP Manual is not a rule or law but represents what the Division believes to be the best way to meet the state’s water quality rules and laws.  The issue of the Division’s flexibility to rely on different management practices or deviations from those in this manual is thoroughly discussed in Chapter 1.  Although many changes were made to the manual as a result of comments received, many comments did not result in a change.  Although many of them may have led to an improved document, the resources needed to perform the analyses to make permanent and statewide recommendations for change were unfortunately not available.  We encourage the public to continue to submit recommendations and especially supporting evidence of improvements that they believe are needed.  Please submit recommendations to either Kelly Johnson, Kelly.p.Johnson@ncmail.net or Boyd DeVane, Boyd.devane@ncmail.net.

North Carolina Stormwater Manual
http://h2o.enr.state.nc.us/su/bmp_manual.htm

NPDES Stormwater Discharge Permit for Construction Activities Fact Sheet
http://www.cicacenter.org/pdf/NCPermitFactSheet.pdf

DENR Regional Office Contact Information
http://h2o.enr.state.nc.us/lab/regions.htm

Links of Interest
http://h2o.enr.state.nc.us/su/Links.htm

Division of Water Quality Stormwater Contacts
http://h2o.enr.state.nc.us/su/
Click on “About the Stormwater Permitting Unit – Contact Information”

Phase II Stormwater map
http://h2o.enr.state.nc.us/su/documents/PhaseII_Update_Map.pdf

Enforcement Contacts - Alabama

STATE ENFORCEMENT CONTACTS

Resource Links