Forest Service researchers collaborated with partners to develop analytic tools that identify specific areas where water drains off forest roads and carries unwanted sediment into waterways. These tools, GRAIP (Geomorphic Road Analysis and Inventory Package) and GRAIP-Lite, informed new Environmental Protection Agency (EPA) policy decisions.
Roads can provide avenues for rain water to rapidly gather and carry sediment across a landscape before flowing into streams and rivers. If a road is poorly placed or designed, the consequences can include degraded local water quality, increased erosion, and an increased risk of landslides among other hazards.
The EPA was exploring the need for additional regulations under the Clean Water Act to make sure forest road runoff does not pollute waterways. The EPA decided that the availability of tools – such as GRAIP and GRAIP-Lite – and institutional programs and rules for road sediment reduction at local, state, and federal levels was already sufficient, and that no further regulations were necessary.
In addition to influencing national policy, the tools are also cost-effective. GRAIP and GRAIP-Lite empower land managers to localize their roadwork efforts on smaller portions of roads, instead of closing down entire sections.
The first step in how GRAIP, developed by the Rocky Mountain Research Station in collaboration with Utah State University, evaluates roadways and runoff is by utilizing traditional manpower and GPS devices to inventory and map a road and its characteristics, such as its slope and alignment. Once a crew finishes inventorying, the data is run through a GIS analysis tool which factors in the road characteristics to predict erosion, sediment movement, landslides, and other risks.
GRAIP-Lite functions slightly differently. It was developed in conjunction with the GIS company ESRI and was funded by the EPA. The Forest Service designed GRAIP-Lite based on results from earlier GRAIP surveys, and then ESRI wrote the programming code. GRAIP-Lite uses GIS to compare and map how much sediment washes into waterways from different roads. It does this using corporate road data. It’s basically a less detailed version of GRAIP that land managers can use to efficiently prioritize roadwork on a larger scale and compare alternative treatment scenario effects on small watershed sediment impacts.
Tools like GRAIP and GRAIP-Lite help society minimize its impact on natural landscapes and in the process save time and money – it’s a win all around.