CITY OF DES MOINES SHORELINE MASTER PROGRAM

Des Moines Shoreline Inventory and Characterization
Table 9. Shoreline Segment “A” Summary
Land Use /
Transportation
Stream
Discharges
Public Shoreline
Access
Hazard Areas
Habitat / Habitat
Potential
Park: 75%, Single-
Family Res.: 17%,
Vacant: 9%; Park
access, foot paths,
beach/auto access
Des Moines
Creek
Des Moines Beach
Park
Erosion, Flood
Wetlands, Stream,
Fish and Wildlife Areas
(Salmonids, shorebirds
and piscivorous birds,
heron rookery, shellfish,
eelgrass)
Shoreline functions within Segment A have been impacted by the following activities:
• Shoreline armoring including riprap (includes mouth of Des Moines Creek) and concrete
bulkheads;
• Removal of marine riparian vegetation;
• Increased impervious surface within the Des Moines Creek basin at a watershed scale;
and
• Changes to the direction of net-shore-drift caused by the Marina (Segment B).
Effects upon the nearshore environment include:
• Sediment supply to nearshore areas cut off by riprap and concrete bulkheads;
• Marine riparian vegetation provides wildlife habitat, microclimates (shade/prey), source
of large woody debris, bank stability, improvements to water quality;
• Subestuaries and deltas depend upon rainfall to bring sediments from upstream to the
nearshore area. High flow rates and volumes resulting from increased runoff from
impervious surface can alter the formation and function of these features; and
• Net-shore drift is the long-term direction of sediment transport along the shoreline. The
construction of the Des Moines Marina (Segment B) has altered this natural process.
Opportunities to improve shoreline functions within Segment A are identified as areas A-1 and
A-2 (Figure 15).
Opportunity Area A-1 and A-2
Opportunities in area A-1 could include the removal of the failing riprap revetment from the
mouth of Des Moines Creek north to the northern City boundary and the removal of riprap from
the mouth of Des Moines Creek. The artificial shoreline could be pulled back a bit with riprap
replaced with alternative “soft shore protection” techniques. Such “biotechnical” or
“bioengineering” techniques could include imported gravel and sand, anchored drift logs or other
large woody debris and , combined with marine riparian plantings along the shoreline and on the
north side of Des Moines Creek. This would allow sediment to migrate from upland areas to the
shoreline, improve subestuary and delta functions, and increase habitat quantity and quality for
both terrestrial and aquatic animals using the shoreline, as well as expanded beach recreation.
Page 40 March 2005