Stormwater Management Blog

NC Minimum Design Criteria (MDC) for Stormwater Control Measures

The Restoration and Recovery team recently attended the North Carolina State University Wet Pond and Wetland Design Update in RTP.  As presented by university and state government employees, the course structured these design strategies within the framework of the recent drafts of Minimum Design Criteria (MDC) Rules for SCMs.  As it stands, MDC rules are a voluntary alternative to the BMP Manual for permits from the state.  Currently, local governments may adopt the MDC in their jurisdictions.  In November the MDC revised draft is scheduled to be codified into rules and supplemented by a stormwater technical guidance manual. For post-construction stormwater management these criteria present a distinct opportunity for regulatory agencies to proactively and efficiently enforce and maintain the quality of SCMs within their jurisdictional boundaries.     

Plants and Your Stormwater Control Measures

Vegetation establishment is an important component of many stormwater control measures (SCM).  Grasses, trees, shrubs, and other herbaceous plants help provide structural stability, conrol erosion, and naturally remove pollutants from rainwater runoff.  However, if proper maintenance is not performed, undesirable vegetation will invade vegetated areas of the SCMs.  If these undesirables go untreated, they can inhibit the function of the stormwater control to convey, treat, and/or store water from storm events.  Furthermore, some desirable plants can become undesirable if they establish in unwanted areas.  For instance, turf grasses invading a planted/mulched area or trees establishing on the floor of a dry detention basin.

Problems Associated with Urbanization and Stream Function

Anyone walking along a degraded urban stream may see signs of the effects of urban development: heavily eroded stream banks, trash in overhanging tree branches, discarded tires, or remnants of stormwater conveyance infrastructure.  It is obvious that intense alterations to the landscape and water network occur when land is developed.   The most immediate consequences include an increase in impervious surface area with resultant increased runoff to receiving streams, higher peak discharges, greater water export and higher sediment loads during construction.  In terms of stream hydrology, an altered flow regime with high peak flows and reduced baseflow is the prevalent effect of urbanization.

Addressing Headwater Drainage with Regenerative Stormwater Conveyance (RSC)

Headwater streams provide many ecologic and water quality benefits.  In a natural setting, these small drainage tributaries filter rainwater, recharge groundwater, and dissipate water velocity while transporting sediment from upland elevations downstream to larger water bodies.  It is not surprising that people tend to populate upland areas where flooding may be mitigated by hard surface stormwater conveyance structures.  As a result of this trend, headwater streams fall victim to residential and commercial development, water quality suffers, and hard surface drainage methods give stormwate

Stormwater Nuisance Issues and Maintenance Solutions

Stormwater Nuisance

There are many preventative measures that can be taken into account for a site-specific stormwater management plan, but even well-maintained and regularly inspected systems can be prone to nuisance issues. Some problems are elusive and could go undetected for a period of time while others are more blatant and are visible to the untrained eye. 

STORMWATER SYSTEM MANAGEMENT DURING THE TRANSITION OUT OF WINTER

Regardless of where your property is located, there are key strategies for proper management of your stormwater system (BMP) year-round. Continuous attention to the system, specifically in the form of inspection and maintenance, is critical in maintaining compliance, preventing failure, and ensuring water quality and quantity standards per design. Monthly, or even more frequent, stormwater maintenance is becoming more of a standard, and is often a regulatory requirement.

Managing Stormwater with LID Techniques

LID Stormwater

To clarify, LID is not something you place on top of your trashcan to keep out unwanted canines.  Since the buzz word, or phrase I should say, has come up in a few of our previous blog posts, I thought it would be worth a brief survey.  Low-Impact Development (LID) is a design and planning scheme that utilizes green infrastructure and stormwater management techniques to mimic the pre-development hydrologic regime of a site.  Five fundamental aspects of LID include:

Chatham Park Planned Development District

Chatham Park Stormwater

A new development underway, Chatham Park, is the local buzz amongst residents of the Triangle area. The 7,100 acre project is located just west of Jordan Lake and the closest town is Pittsboro. According to the Planned Development District Master Plan, Chatham Park is envisioned as having five villages. Creeks and stream valleys will serve as natural buffers between neighborhoods and as trail connection points connecting neighborhoods.