Wetland Classification and Mapping of the Kenai Lowland, Alaska

 

Map Unit Descriptions

 

Ecosystem: Tidal

 

Map Unit: T76; T67

 

Extent:

T76: 2 wetland polygons; 5.5 ha; 0.00% of wetland area; 0.01% of wetland polygons.

T67: 1 wetland polygon; 7.7 ha; 0.01% of wetland area; 0.01% of wetland polygons.

The only T67 wetland, at the mouth of the Anchor River (polygon 28167).

Wetland Indicators

Type: Tidal

Average depth to water table:

T6: 11.5 cm; n=2

T7: 22 cm; n=1

Organic layer thickness:

T6: 19 cm; n=1

T7: n/a

Average depth to redoximorphic features:

T6: 0 cm; n=1

T7: 0 cm; n=1

Common Soils:  CLUNIE

Common Plant communities:

T7 Component:

Beachrye

 

T6 Component:

Lyngbye's sedge

 

Only two wetlands were mapped as T76, both were near the mouth of Deep Creek, neither of them exits today.  They were visited in 1999 as part of the Natural Resources Conservation Service Western Kenai Soils mapping effort; no photographs were taken.  During the October and November of 2002 significant flooding events (>100 year) occurred, washing out the Sterling highway bridge and changing the course of Deep Creek.  The mouth of the creek now empties into the inlet about 0.2 miles southwest of where it did before the floods.  Large amounts of gravel and sand were deposited in the estuary.  With time, the original plant communities may return to occupy locations similar to their historic occurrence, or new plant communities may develop.

 

Both original wetlands were dominated by beachrye (T7) with a mix of Lyngbye's sedge (T6).  Vince and Snow (1984) describe 'Riverbank Levees' dominated by other grasses, and that "Still higher levees featured [Beachrye] and large forbs..."  Their lower elevation riverbank levees flood an average of 1 time per summer; higher T7 beachrye berms or levees probably flood only when large storms correspond with spring tides. 

 

T6, the Lyngbye's sedge community, corresponds with Vince and Snow's (1984) 'Inner Sedge Marsh Zone 7', estimated to be inundated on only the highest spring tides, or an average of 2 times per summer on the Susitna Flats (with a range of 0-5 times per summer).

 

The single T67 wetland is dominated by Lyngbye's sedge, with small islands of beachrye, near the mouth of the Anchor River.

 


 

 Introduction and Key to Plant Communities  

Introduction and Key to Ecosystems

    Kenai Hydric Soils    Map Unit Summary    Methods    Glossary

 

Contact: Mike Gracz
Kenai Watershed Forum 
Homer Field Office
Old Town Professional Center
3430 Main Street Suite B1
Homer, AK  99603
907-235-2218

15 November 2005 15:04