site assessment lgog

Once a project is selected, landscape ecology, watershed information, and other relevant data can be used as  art of the site assessment process for buffers. The site assessment process often varies depending on the  watershed goals and general design concepts for the buffer. The following table summarizes primary information to be collected for site assessment and lists how the information may influence design. 


Importance for Vegetation Plan Development

Site Topography and Contours

Potential areas of nutrient and pollutant  concentrations as well as planting zones, seed  mixes, and other planting strategies. 

Geology and Soils Information

Erosion potential as well as nutrient levels and infiltration rates.

Land-Use Information from Aerial Photographs and Site Visits

Possible threats such as invasive species, nutrients, and changing water levels. Will help determine where buffers and corridors can be most effective to reduce fragmentation, connect remnant patches, and decrease edge effect.

Subsurface Drainage

In agricultural areas drain tile may bypass a buffer, creating a need  or additional conservation practices to treat nutrients. 

Previous Land-Use

Look for evidence of sedimentation of wetland basins or other erosion problems, the introduction of aggressive species, as well as fertilizer, herbicide, and pesticide use. 

Historic Vegetation

Helps to select plant communities and species appropriate for the site.

Existing Seedbank Potential

A threat or a benefit, it may influence the planting strategies, seed  mixes, and control efforts. 

Site Photography

Aerial and ground-level images can be a good reference during  buffer plan development. Also useful for tracking restoration  establishment.

Existing Native Vegetation

Planning for site preparation, planting, and maintenance strategies.

Existing Invasive Vegetation

Understand invasive risk aids planning for site preparation, planting,  and maintenance strategies

Reference Plant Communities

Native plant communities in surrounding areas help assess project
opportunities and potential challenges.

Hydrologic Data

Pezometric data may reveal groundwater flow. Stream or ephemeral
overland flow could influence buffer placement.


A variety of GIS data for Minnesota is now available on the Minnesota Geospatial Information Office such as original land survey maps, Lidar data, and air photos.

It is helpful to create a site assessment diagram that illustrates how site conditions will influence project design. Site assessment diagrams can be sketched quickly and tend to include: location of waterbodies,  physical structures, roads, walkways, fields, areas of steep slopes, drainage-ways, remnant vegetation, existing buffers, and locations of invasive species. Essentially, anything that will influence the project design can go on the site assessment diagram.

As a site is assessed, project opportunities may become more apparent and project goals, objectives, and outcomes can be further refined. For example, a site connected to a natural plant community with low invasive species pressure may be found to provide many wildlife benefits in addition to water quality improvement.

Site Assessment Diagram

site assessment diagram

This site assessment diagram shows an existing wetland, moist soils and a drainage-way north of the river that will each influence design strategies to improve wildlife habitat and nutrient treatment. South of the river slopes and narrow buffer widths are identified to guide planning to meet the state’s buffer law.


Dan Shaw
Senior Ecologist/Vegetation Specialist