|
|
MIDCOAST 6TH FIELD WATERSHED
ASSESSMENT |
WATERSHED
ASSESSMENT IS ONLINE
Project Description:
This
project was conducted by Earth Design Consultants, Inc. and Green
Point Consulting. We worked with the MidCoast Watershed Council (MCWC) to
use existing information to analyze and prioritize 6th field watersheds in the
Alsea, Salmon, Siletz, Yaquina, and coastal watersheds. Project
Length: 24
months Study
Area: 
Approach
Task 1. Build core data layers.Watershed
assessments are a management tool. To guide recommendations and action plans,
the tool must be constructed from data that accurately describe watershed conditions.
Certain data layers are key to the process because they form the base on which
other data and management decisions are built. Built from core data layers,
the base map determines the degree of detail at which the analyses of watershed
conditions can be performed. These core data include: Streams and other
water bodies; Land cover (vegetation, bare ground, urban areas, etc.);
Roads; Terrain (including stream gradients, channel confinement,
and watershed morphometry); Fish abundance and distribution; In-stream
conditions (for example, gravel, pools); Water quality; Land use
(zoning); Soils; and Geology. Building
core data layers involves three specific tasks: (1) critical review of existing
data, (2) identification of data gaps, and (3) development of new data.
Task 2. Develop comprehensive
analyses of watershed conditions from core data.Geographic
information systems (GIS) data are spatially explicit and geographically referenced,
and can be analyzed and manipulated in ways that are uniquely useful in understanding
watersheds. The GIS-based analyses performed in this step is based on concepts
and approaches in the current (1999) draft of the GWEB Watershed Assessment
Manual. As with other steps, analyses performed are made only after thorough
discussion with MCWC. Examples of these GIS analyses include: Length of source,
transport, and deposition reaches by watershed, using DEM-generated streams layer;
Length of confined and unconfined stream reaches by watershed, using DEM-generated
streams layer ; Land cover versus fish presence/abundance; Debris flow/mass wasting
risk areas (slope and slope morphometry versus soil type); Riparian cover versus
fish presence/ abundance. Task
3. Develop a list of recommendations and priority actions for the watersheds,
along with rationale for the list.Recommendations
and priority actions are defensible, because they are based on analyses conducted
using solid, critically-reviewed data. Along with the list of recommendations
and priority actions, we expect to establish quantitative benchmarks for watershed
parameters, which can be compared in the future to new values obtained through
monitoring (Task 4). Task
4. Make recommendations for future monitoring.We
believe that monitoring recommendations are a key part of any watershed assessment.
Monitoring is vital to determine success of restoration efforts, to fill data
gaps, and to keep existing data layers up-to-date. With well-planned monitoring,
the MCWC's understanding of the watershed will improve greatly over time. The
Council will be able to document watershed changes and revise action plans accordingly.
This process of "adaptive management" will maximize the chances of successful
watershed management. Task
5. Attend meetings of the MCWC and its technical advisory team, and maintain close
communications with MCWC members.Throughout
this project, we have emphasized the importance of joint discussion between our
team and the MCWC. Ongoing discussions will be used to guide central decisions
in this watershed assessment. We will maintain close communication with the MCWC.
Reports
& PublicationsBrophy,
L. and R. J. Garono. 2000. GIS as a Tool for Watershed Assessment: Working Toward
a Desktop Decision Support System. Proceedings of the 17th International Conference
of The Coastal Society, Portland, OR USA. 592. Garono,
R. J. and L. Brophy. 1999. Using A Geographic Information System (GIS) To Prioritize
Monitoring And Restoration Activities In An Oregon Coastal Watershed. Proceedings
of American Water Research Association. For
more information contact the
Contact Information
Wetland
& Watershed Assessment Group Earth Design
Consultants, Inc. 230 SW Third St., Suite 212 Corvallis, OR 97333 (541) 757-7896
(541 757-7991 FAX http://www.earthdesign.com |
|
| |
