Portland Oregon Wetland Delineation & Water Resource

Development projects often require determining the location and type of potential wetlands located on your site. The location and amount of wetlands is very important to be aware of when developing in Oregon & Washington. Wetland delineations entail mapping the precise location of wetlands by observing overall site conditions, plant types and soil types. Environmental Management Systems (EMS) explores options to avoid impacts. If impacts are unavoidable then our Wetland Delineation experts at Environmental Management Systems can assist with mitigation, enhancement, relocation or alteration of the wetlands in Oregon & Washington.

Are There Wetlands on Your Land?

A YES answer to any of the questions may indicate that the area is a wetland. A site inspection by a qualified wetland scientist is the only way to verify whether an area is a wetland or not.

Yes / No

  • ____ Does the National or Local Wetlands Inventory map show a wetland on the property?

  • ____ Does the county soil survey map show hydric soils within the site?

  • ____ Are there natural drainage channels or swales?

  • ____ Is the ground soggy underfoot in the spring?

  • ____ Are there depressions where water pools for a week or more in the spring?

  • ____ Do you avoid the area with heavy equipment in the spring to keep from getting bogged down?

  • ____ Would you need to ditch the site to dry it out for planting or building?

  • ____ Are seeps or springs present?

  • ____ Dig an 18-inch deep hole and remove a clump of soil. Are there rusty red “mottles” on a gray background?

  • ____ Is there evidence of surface scour from water flowing over the site? Is there a drift line of leaves or debris caught in the stems of shrubs or lodged along an elevation contour?

  • ____ Do you see many clumps of grass-like rushes (round stems) or sedges (angular stems), skunk cabbage, willows, or Oregon ash? (These are just a few of the many plants that grow in wetlands.)

  • ____ If farmed, must you work the soil later than other areas because soils are poorly drained?

  • ____ Did the area fail a septic system test and/or require a special system due to poorly draining soils?

Next Steps: If you think you may have a wetland in an area in Oregon or Washington where you propose earth-moving activities (fill or excavation) or construction, verification by a professional wetland delineation expert is recommended. We can evaluate the site and prepare a wetland determination report.

Reports may be submitted to DSL for verification and explanation of permit requirements.