OVERVIEW

SEF has provided wetland identification, delineation and mitigation services for individual building sites, housing developments, industrial sites, golf course development and

agricultural operations. Company staff has worked closely with the U.S. Army Corps of Engineers, Oregon Division of State Lands, U.S. Fish and Wildlife Service, Oregon Depart.

of Fish and Wildlife, Oregon Department of Forestry and the U.S. Natural Resources Conservation Service in conjunction with wetland related projects

Over the past five years the company has conducted wetland inventories and delineations for fresh water and tidal areas from the South Coast (Brookings) to the Siletz River.

SEF has produced site location maps, delineation maps, mitigation maps and cross sections for the projects listed below. All the photo interpretation and mapping is done in-house. Field data that is gathered electronically or manually is converted into our CAD drafting program for interpretation and calculations. The basic CAD systems we utilize is AutoCAD, ArcCAD and ArcInfo formats which can be exported using a DWG file or DXF format which is compatible with Intergraph. Draft maps are produced on either a laser printer in an 8½" x 11" format or can be plotted using pencil or ink on 18"x24" and 24"x36" formats. Designation of different areas are identified through a combination of line types, widths and cross hatching patterns that can be plotted on mylar and reproduced through standard blueline machines. Our system can also produce ink jet color reproductions of aerial photographs with property lines, topographic lines and delineation overlays on 8½" x 11" to 24" x 36" formats. This product has been very useful because it gives a full color, visual representation of the project site.

Methods employed in the various assessments include aerial photo and topographic analysis combined with soils data and specific property location maps. These tools are used to support the site inspection and evaluation. A general reconnaissance is conducted to confirm the location and site conditions of the study area. A local control point is established to provide a base location for measurements. Depending on the size and scope of the project, data is collected using an engineers’ tape, string chain and compass, or conventional survey equipment. Resource grade GPS is available when appropriate. SEF uses the Trimble Proxl system with a 12-channel differentially corrected position. The system is a sub-meter accuracy system (less than 3.0 feet horizontal).

Typical project sites range in size from less than 1,000 square feet to 20+ contiguous acres. The assessments have involved tidal influence wetlands, degraded wetlands behind tide gates, farmed wetland pasture, freshwater wetlands hydraulically connected to estuarine areas and hydrologically isolated freshwater wetlands.

Determining the functions and values of individual wetlands is an integral part of each wetland project. The general relationship of the wetland site with adjacent lands is evaluated then site specific data is collected. Existing plant communites are identified, soil test holes are dug and the water table is determined. Soil samples are analyzed for hydrological characteristics and coded according to the Munsell Classification. The field data is recorded, analyzed and mapped. The services and expertise of Dr. Ben Fawver are used to identify exotic plant species and uncommon plant species. Certain plant species in transition areas between wetlands and uplands often help determine the boundary between the areas.