Bathymetery data provided by Paul Marshall from DWR was converted
to 3D model to help the viewer understand exactly where and what “the
obstruction” is at the head of Steamboat Slough. Despite Mr.
Marshall’s assertion the shoal is “naturally occuring” the steepness of
the underwater walls shown in the sonar views, and the fact an
underwater camera showed rock piles indicates this “obstruction” is
something other than naturally occuring, at least when the obstruction
was first installed.
19 feet
deep
SUTTER
ISLAND
8-10
feet deep
11 feet
deep
ROCKS
35 FEET DEEP
GRAND
ISLAND
Bridge
Red dots show the likely migration pathway ouf outmigrating salmonids
19 feet
deep
SUTTER
ISLAND
8-10
feet deep
11 feet
deep
ROCKS
35 FEET DEEP
Bridge
GRAND
ISLAND
Water depths based on depth finder and sonar from a boat at mid and low tides in May 2014
Sutter Island
Grand Island
Narrow channel for upmigrating adult salmon ... IF they migrate into lower Steamboat Slough’s low flow waters
Depths at low tides in May 2014
Grand Island
35’ deep
12 ‘ deep
8’ deep
Sutter
Island
19-21 feet deep
Sacramento River
Sutter Island
35 ‘
deep
8’ deep
19-21’ deep
10-12’ deep
Sacreamento River
Colors based on the bathymetery provided by Paul Marxhall, DWR June 2014, the color scale of the Marshall
data, compared to the depthfinder and sonar readings from a boat in May 2014
19-21’ deep
Sutter Island
8-10’ deep
11-12’ deep
35’ deep
Grand Island
Note that sides of the narrow channel or rut leading into the head of Steamboat Slough are smoother
that depicted. 3D graphic was made from data provided by Paul Marshall, DWR, June 2014.