The MidCoast Watersheds Basin Browser is a static
web application built with ArcGIS 8.1.2, Alta4's HTML ImageMapper
8.1, Access 2000, and Adobe Acrobat 5.0. The underlying data is
largely derived from the MidCoast Watersheds Council's Sixth Field
Watersheds Assessment supplemented with additional data from state
and federal agencies.
When the reports refer to benchmarks or desirable conditions,
they are referring to the Oregon Department of Fish and Wildlife
habitat quality benchmarks as outlined in the GWEB/OWEB Oregon
Watershed Assessment Manual.
A brief description of the data used on the text portions of the
subbasin reports (PDF files) follows:
| Data |
Source |
Description |
| 5th Field Watersheds |
Assessments |
5th field watershed outlines and descriptions were taken
from the assessment. |
| 6th Field Watersheds, area, & HUC's |
Assessments |
6th field watersheds were the base unit for the assessment. |
| Stream Length @ 1:100K scale |
Assessments
/ [L_100KSTRE] |
Stream length @ 1:100K scale provides a base stream layer
with coverage for the complete assessment area, however, it
has relatively low resolution and underestimates stream length
by a large margin when compared to 1:24,000 streams layers. |
| Road Density |
Oregon BLM GIS |
Road density was calculated by using the BLM roads layers
for the Eugene and Salem districts. The layers were merged,
then clipped and summarized by sixth field. This measure is
approximate due to variation in the underlying data sources
and should be used with great caution. The assessment did
not use this data. |
| Length Surveyed |
Assessments
/ [LENGTH_ALL] |
Total stream length of aquatic habitat inventories on streams
in each subbasin was calculated for all agencies/protocols.
This measure is approximate due to variation in the underlying
data sources and should be used with great caution. |
| Average Large Wood |
Assessments
/ [LWD_ALL] |
Average density of large wood in streams in each subbasin
was calculated for all agencies/protocols (where possible). |
| Average Shade |
Assessments
/ [SHD_ALL] |
Average percent shade along streams in each subbasin was
calculated for ODFW and Lincoln Soil and Water Conservation
District surveys. |
| Survey Length Index |
Assessments
/ [SURV_INDEX] |
The Survey Length Index is the ratio of the total surveyed
stream length in a subbasin to the total stream length on
the 1:100K scale streams layer. This index does not precisely
indicate the fraction of streams that have been surveyed but
does give a rough estimation of how thoroughly the streams
in an area have been surveyed. |
| Number of Pools Surveyed |
Assessments
/ 1998-1999 Rapid Bio-Assessment Data / [NPLS9899] |
The number of pools surveyed in the snorkel surveys of 1998-1999. |
| Average Coho Density |
Assessments
/ 1998-1999 Rapid Bio-Assessment Data / [COSQ9899] |
Average Coho juvenile density in the snorkel surveys of
1998-1999. |
| Average Complexity |
Assessments
/ 1998-1999 Rapid Bio-Assessment Data / [PLCO9899] |
Average pool complexity in the snorkel surveys of 1998-1999,
with 1 representing no complexity and 5 representing very
high complexity. |
| 303(d) Listings |
DEQ
Online 1998 303(d) list coverages |
303(d) listed streams and lakes were identified by intersecting
the Oregon DEQ's coverages of listed streams and lakes with
the 6th field watersheds and adding an internal table to the
Basin Browser application to identify subbasins with listed
waterbodies. For more information, consult the DEQ's 303(d)
list as the document of record. |
Data used on the report maps includes:
| Data |
Source |
Description |
| Coho Density / Pools |
1998-1999
Rapid Bio-Assessment |
Pools are placed along the streams and shaded to indicate
relative coho juvenile density. The shapefiles are available
for download from the source page. |
| 5th and 6th field watersheds |
See above table. |
See above table. |
| Streams |
Siuslaw
Nat'l Forest Densified Streams / National
Hydrography Dataset |
The streams layer is produced by the Siuslaw National Forest
and has accurate to 1:24,000 scale. |
| Roads |
2000
US Census TIGER |
Roads were extracted from the US Census Bureau's 2000 TIGER
line files. TIGER lines were used because of their high quality
name data for ease of labeling. |
| City and County Outlines |
Oregon
Geospatial Data Clearinghouse |
City and County boundaries were downloaded from the OGDC;
city outlines are 1:24,000 scale while county outlines are
1:100,000 scale. |