DEP Stormwater management
Local Communities with Stormwater OrdinancesLow Impact Development
Huntingdon County Retention Ponds and Rain Gardens (pictures taken on Nov. 20, 2007)
Meadowcrest Condominiums Boney Forge, Mt. Union
Raystown Lake Resort and Conference Center
Meadowcrest Condominiums is the development of 21 duplex condos and related infrastructure located on about 17 acres. The BMP's used during this project are a rock construction entrance, sediment basin, detention basin (2), stone diversion swales, and 18'' high silt fence.
The Boney Forge site is a 60,000 sq. ft. warehouse facility on Lots 11-16 of the Riverview Business Park and adjacent parking areas. The BMP's used during the project are a rock construction entrance, collection and diversion ditches, sediment basin, silt fence, erosion control blankets, bio-retention forebay, and inlet protection.
Raystown Lake Resort and Conference Center
This project involves the development of a 29,000 sq. ft. conference center and rental cabins at the Lake Raystown Resort located in Lincoln Township, Huntingdon County. The BMP's used during the project are a rock construction entrance, silt fence, bio-retention rain gardens (a series of vegetated bio-retention rain gardens to collect runoff from the parking area as well as the conference center itself), and roof water infiltration sumps (captures roof water and infiltrates it into the soil).
Erosion control BMP's
This roadway is used for residential and hunting purposes. The roadway problems consisted of steep slope/transition from paved roadway at the top of the slope discharging stormwater to Ponderosa Road, rip-rap in roadside ditch washing out due to high flow rates, and it needed new cross pipes. The solutions to the problems were a driving surface aggregate, R7 stone to line roadside ditch, new cross pipes, and the incorporation of plunge pools about every 30 feet in the ditch to slow down stormwater flow rate.
Flood Plain - is the relatively flat land near a body of water that experiences occasional flooding
Infiltration - is the penetration of water through the ground surface into sub-surface soil
Typical Erosion Control BMP's
Rock Construction Entrance - rids construction equipments tires of debris and sediment keeping sediment onsite to be handled by onsite facilities during construction
Inlet Filter Bags - used in stormwater inlets to trap sediment/particles greater than 150 microns
Erosion Control Blankets - temporary BMP ranging from natural to artificial materials using fibers to keep soil in place preventing erosion until vegetation is established. It is typically used on slopes steeper than 3:1, and in areas of highly erosive soils, low fertility, and in drought conditions.
Silt Fence - used to control runoff and capture sediment from small disturbed areas in sheet flow areas
Silt Soxx - used to control runoff and capture sediment from small disturbed areas in sheet flow areas and concentrated flows. Benefits to silt soxx as opposed to silt fence include easy to remove after vegetation is established/cut open and spread the mulch, compost within; can be used in areas with rocky soils because they are on the surface rather than trenched into place like silt fence.
Channels and Channel Linings (vegetated, matting, rock lining) - provide protection within channels and channel slopes preventing erosion of soil. It can be used to divert offsite stormwater away from project site, collect onsite stormwater and conveying it to a stormwater facility for retention or removal.
Sediment Basins - captures stormwater runoff from disturbed areas and returns it until sediment falls out and the "clean" water is discharged to a stable area or waters of the commonwealth. After site construction is completed these basins are often converted into post construction stormwater facilities, i.e. retention/detention basins.
Sediment Traps - used to capture sediment from runoff from disturbed areas and discharge sediment free stormwater to a stable area. These are essentially are small temporary sediment basins.
Infiltration basins - are shallow impoundments that temporarily stores and infiltrates runoff over a level, uncompacted, preferably undisturbed area with relatively permeable soils. They work well to control runoff for new development.
Rain Gardens - are excavated shallow surface depressions planted with specially selected native vegetation to treat and capture stormwater runoff. Rain gardens typically consist of a rock layer under drain wrapped in geotextile to prevent clogging pore space with a highly porous soil placed at the surface for planting native vegetation. Rain gardens are designed to reduce runoff volume, filter pollutants, recharge groundwater via infiltration, reduce stormwater temperature impacts, enhance evapotranspiration, enhance aesthetics, and protect habitat.
Retention/Detention Basins - This is the most typical form of stormwater runoff control used in areas of development. These are shallow impoundments placed down slope of large earth disturbances to capture stormwater and allow retention, infiltration, evaporation, and evapotranspiration to occur over a period of several days.
Porous Pavement/Concrete - pavement with large pore spaces to allow water to drain and be temporarily held in the voids in the stone bed, and then slowly drains into the underlying uncompacted soil mantle. A layer of geotextile is wrapped around the stone bed layer to prevent fines from clogging pore space and preventing stormwater from draining through the pavement/concrete. Pervious pavement is well suited for parking lots, walking paths, sidewalks, playgrounds, plazas, tennis courts, and other similar areas.
Rain Barrels - a barrel or large container that collects drainage from roof runoff and store it until it can be reused for irrigation.
Green Roof/Vegetative Roof - an extensive vegetated roof cover is a veneer of vegetation that is grown on and completely covers an otherwise conventional flat or pitched roof endowing the roof with hydrologic characteristics that allow for stormwater capture rather than runoff. This form of stormwater BMP allows evaporation and evapotranspiration to occur rather than a typical impervious roof surface causing stormwater runoff.
The future of stormwater management in Huntingdon County as well as the rest of the state is transforming from your typical bio-retention basins. They are transforming from detention basins to more infiltration such as green roofs, bio-retention rain gardens, infiltration basins, silt soxx in place of silt fence, porous pavement with infiltration beds as opposed to regular asphalt for parking areas and sidewalks, and rain barrels for capture and re-use of roof runoff.