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PSNERP-Nearshore Science Team (NST)
Monthly Meeting Synthesis
13-14 July 2005

Attendance

Si Simenstad (UW), Miles Logsdon (UW), Curtis Tanner (USFWS), Fred Goetz (ACOE), Tom Mumford (WA-DNR), Guy Gelfenbaum (USGS), Bernie Hargrave (ACOE), Phebe Drinker (UW), Doug Myers (PSAT), Hugh Shipman (WA-DOE)
Visitors: Bill Hinesley (Everglades Restoration Plan; Louisiana LCA); Marina Alberti (Urban Ecology – UW)

Primary Meeting Topics

1. GI Feasibility Report
2. Future without Project Conditions
3. Science Morning: Management Measure Case Study—Dam Removal, Elwha River dams
4. WRIA9 Current Conditions and Change Analysis

Science Synthesis (Science Morning)

NST member Guy Gelfenbaum (USGS) used the Elwha River dams removal as a case study to illustrate the restoration implications to adjacent nearshore ecosystems. He described the key components of fish passage, marine-derived nutrients, fluvial restoration, and sediment supply from the perspective of the on-going and anticipated USGS research activities. He also touched on research that other agencies (e.g., NOAA, tribes) are conducting, acknowledging that coordination has been minimal so far. There have been two workshops on the topic of nearshore responses; one public-oriented and one more technical (Dr. Bob Naiman’s UWEI workshop). In particular, the April 2004 workshop addressed several issues about sediments released in the dam removal process: sediment pathways, dispersal processes, and how riverine and nearshore ecosystems might be effected.

The primary research questions driving the current USGS studies described by Dr. Gelfenbaum relate to sediment transport to nearshore ecosystems. A large amount of sediment is stored in a relatively short system (from headwaters to release point) behind the dams. The two primary sediment sources—erosion within the reservoir and sediments coming down river itself—are perceived to impose potential impacts as well restoration benefits to nearshore ecosystems. Based on estimates by the Bureau of Reclamation (Randle, et al.), sediments transported through system (3 yr and 50 yr interval) from the erosion behind the dams are not expected to be a high percentage and most erosion is predicted to occur as a result of notching and hydrologic events. Sediment transport through the river, also estimated by the Randle group, suggested that all eroded fine sediments would be transported over 3 yrs, but once in the Strait of Juan de Fuca, the transport process and distribution could change (e.g. hyperpycnal plumes – below pycnocline). In comparison, less (26-52%) of the course sediments will be transported and the lower river is predicted to regrade. Over 50 yr, these numbers will change. Ultimately, 5-6myd3 mud and 2-1.5myd3 sand and gravel (pre-dam = 0.1) will be delivered to nearshore ecosystems. This is roughly estimated to result in about 1m sediment accumulation spread over river mouth, but note that this may be influenced by large eddy that forms off the mouth of the river! Considerably work by the Tribe, NPS and others have concentrated on historic change in the river channel and the delta that could be interpreted as resulting from the dams’ effects on sedimentation processes downstream and in the nearshore region. The USGS (Coastal and Marine Geology Group) sediment studies are focusing coastal mapping, process-based spatially-explicit morphological modeling, and process measurements. Coastal mapping has illustrated seasonal changes in the delta, illustrating 40m progradation between summer and winter. Sonar and video mapping of bottom substrates indicate extensive and complex variation in sediment sizes and bedforms. The process studies are linking nearshore current and salinity dynamics to the observed changes in bathymetry and sediment structure, and are using the DELFT3D model with sediment transport. They are also examining the bathymetry of Ediz Hook, to evaluate how much sediment that feeds Ediz Hook originates from river discharge and delta as compared to bluff erosion.

This synthesis of the on-going Elwha Dams removal studies illustrated several issues about scientific assessment of demonstration projects: Will the signal be big enough compared to natural variability (in terms of sediment movement, beach morph, and habitat)? May not be able to acquire accurate measures of variability in only 2-3yrs; may be multi-decadal variation! And, historic shoreline change “data” isn’t much data at all and may not account for tidal changes, season, etc.

Final comment based on this discussion of our general NST approach to learning about and formulating management (restoration/preservation) measures is that, perhaps more than VEC’s, the PSNERP community could use ‘white papers’ on different management measures.

Status and Action Items

GI Feasibility Report

Fred Goetz led a discussion about purposes and organization of USACE feasibility reports, using the Louisiana Coastal Area (LCA) as an example. Important points of NST relevance were: NST has most input:

(1) problem identification—What are the causes of problem?

(2) plan formulation—Qhat is it we need to do? What will we get out of it? What are our scales? What are the VEC linkages, i.e., in terms of “benefits?”

(3) The NST conceptual model will help justify or explain best available science for basic assumptions behind. A cost-benefit analysis will have to be an element of the benefits analysis, but NST will have a role in determining how this analysis is conducted, especially from the perspective of contingent and other indirect economic benefits.

The NST recognized that it needs to create

(1) an organizational process map (“road map”) and

(2) a geospatial map of restoration needs and potential (alternative) solutions. Thus, the end product of immediate need and utility is a “road map” that describes organizational process to get to a “non-specific solution map” (NSSM), that includes:

(a) steps, linkages to get to viable solutions;

(b) identifies what nearshore ecosystem processes are broken and where; and

(3) provides generic solutions that is backed by a quantified objective for amount of change desirable (15% more sediment delivery).

Future Without Project Conditions

The Future Without Project Conditions analysis is an extension of trajectories from Historic analysis that is framed by Problem Statement and is both a projection (from historic trends) and prediction (based on driving variables) of future conditions if this project isn’t carried out. Fred Goetz and Bill Hinesley (guest) described this analysis based on the LCA feasibility report. Dr. Marina Alberti, UW Urban Planning Professor, presented some perspective on how her group would approach a Future Without Project Conditions analysis based on a joint fact finding approach. She described information sources and analyses (e.g., Land Cover Change Model [LCCM] for Central Puget Sound) that are being used presently to address similar sorts of questions. Dr. Alberti and her colleagues are candidates for PSNERP funding to assist in designing approach to Future Without Conditions analyses.

WRIA9 Current Conditions and Change Analysis

For current conditions in WRIA 9, CommEnSpace will proceed to

(a) complete WRIA9 historic conditions with inclusion of missing data (e.g., upper Duwamish);

(b) develop rulesets that cover shore types that were not included in WRIA9 (primary candidate area is Whibey Island Basin); and,

(c) develop different methodology for typing shoreline that will rely on better data sets (higher resolution, bathymetry, etc) to develop typology, e.g., a data-driven, rather than interpretation, effort.