KRIS Garcia River: Meta Information Page

Meta Identifier	O'Connor_LWD
Type of Data	Large woody debris surveys
Originator	O'Connor Environmental/Mendo Co RCD
Description	O'Connor Environmental conducted surveys of the volume and type of large woody debris in twelve Garcia River tributaries, as part of the Garcia River Instream Monitoring Report (see Maahs and Barber, 2001). The surveys protocol was modified from Washington Forest Practices Board (WFPB, 1995) methodology. In addition to the WFPB approach, riparian stand assessments were also conducted according to California Wildlife Habitat Relationships (WHR) criteria (CDF, 1988).
Area	Garcia River tributaries
Metadata Date	6/12/03
Metadata Contact	Eli Asarian
Contact Person Primary	Matt O'Connor
Status	complete
Access Constraints	None
Lead Person	Eli Asarian
Lead Organization	KRIS IFR
Data Set Name	wood_gar_barber_1999.db, wood_gar_barber_1999_source.db
Date of Content Start	1/27/99
Date of Content End	4/15/99
Maint. and Update Freq.	One time exercise
Supplemental Information	Garcia River TMDL addresses roads and erosion and abatement of potential sources (US EPA, 1998). Euphrat (1998) and PWA (1998) also addressed road issues in the Garcia River basin.
Counties	Mendocino
Keywords	Large wood, LWD
Publisher	Mendocino Co. Resource Conservation District
Publication Date	2001
Title	The Garcia River instream monitoring project. Final report to California Department of Forestry
Abstract	The Garcia River Instream Monitoring Project was a pilot cooperative project that documented current channel conditions and established baseline monitoring data for a North Coast timber producing watershed with anadromous fish. The project was conducted in two phases. The first phase was a watershed assessment and instream monitoring plan (1997-1998), and the second was implementation of the instream monitoring plan (1998-1999). The objective of the project was to document current instream channel conditions in Garcia River tributaries that could serve as a baseline, which could later be revisited to determine the effectiveness of California’s Forest Practice Rules in protecting salmonid habitats. The utility of the Instream Monitoring Project is intended to develop with time, as monitoring stations are revisited and information is collected and compared to that collected in the baseline inventory. In this way, trends may be identified to indicate whether channel conditions are improving or declining, both within and among the surveyed tributaries. Twelve sub-basins within the Garcia River (Figure 1) were monitored. Parameters measured included water temperature, gravel composition, gravel permeability, large woody debris (LWD), channel cross-sections, thalweg profiles, riparian canopy and shading, sediment transport corridors, a spawning survey, and to a very limited degree, turbidity. Five separate contractors conducted the sampling for these parameters. Four plots were established for the 12 tributary reaches, with plot length defined by estimated bankfull width. Spawning survey information was the only information available to characterize the population levels of Garcia River salmonids. Out-migrant trapping of juvenile fish would have provided a better indication of current habitat conditions, but available funding was not sufficient for this level of monitoring. Water temperature Data were collected at the upper and lower ends of study reaches, and a complete set of Data were collected from mid-May to mid-October 1999 in flowing water to reflect average water conditions. Maximum weekly average mean and maximum weekly average maximum summer water temperatures were determined for each tributary. Maximum weekly average temperatures (MWATs) exceeding 17.4o C, calculated with the highest 7-day moving average of maximum daily temperatures, were found on 6 of the 12 tributaries monitored. All of the six coastal tributaries were below this threshold. A recently developed MWAT model developed for predicting presence/absence of coho salmon based on temperatures in thermal refugia was applied to the data set. The model predicted coho in all the coastal tributaries evaluated, while none of the inland tributaries were predicted to have coho present. Canopy cover Data were found to be correlated with maximum water temperatures (r2 = 0.60 for all 12 tributaries). Average Garcia River canopy density was found to be 64%, while average shading determined with a Solar Pathfinder was reported as 71% in July. Spawning gravel composition and gravel permeability was measured in 10 of the 12 tributaries. The relationship between permeability and the bulk samples explained 45% of the variability (r2 = 0.45), with the remainder of the variability hypothesized to be due the packing of substrate particles. The basin average for percent fines (<0.85 mm) was found to be 8.2% utilizing the dry sieving method. Earlier work in the Garcia River watershed produced a much higher average for fine sediment with wet sieve data (for example, the Garcia TMDL lists the percentage as 20.6% with wet sieve data). Mean gravel permeabilities were approximately 3,000 cm/hr, with means for the various tributaries ranging from approximately 1,700 to 5,000 cm/hr. These values are generally considered to be in the lower portion of the moderate range for permeabilities. It was concluded that permeability showed the potential to define variability in spawning gravel quality with better resolution and lower cost than McNeil bulk samples—but the relationship between permeability and egg survival has yet to be established and quantified. For the Garcia as whole, LWD loading was estimated to be 385 m3/ha (compared to an average of 220 m3/ha in second growth redwood/Douglas-fir watersheds, and 1,200 m3/ha for old growth stands). Over half the LWD was found in accumulations or larger jams; approximately 60% was redwood and 25% hardwood. Most LWD was sound and mildly weathered and about 25% of the pieces were pool related. The recruitment rate was estimated to be 3.7 m3/ha/yr, compared to 5.3 m3/ha/yr documented at North Fork Caspar Creek. The recruited wood was a mix of hard and softwood classes with average diameters smaller than 0.5 meters. In contrast, long-lasting, geomorphically significant instream pieces are most often redwood with large diameters. Sediment transport corridors (STCs) are visible corridors allowing sediment to enter stream channels and provide linkages to current sediment generating mechanisms on hillslopes. STCs were evaluated for the plots located within the 12 tributaries. Delivery potential, restoration priority, and possible machine restoration were rated. Most of the surveyed STCs were road and crossing related landslides and gullies. Many were failed crossings that diverted tributaries down roads, and most sites were judged to be inaccessible to heavy equipment due to crossings being washed out. Spawning surveys were continued in the Garcia basin. Approximately 29 km (18 mi) of the upper mainstem and 12 of its tributaries were surveyed, for a total of 134 km (83 mi). No live coho or coho carcasses were observed during the winter of 1998-1999. Approximately two steelhead redds/mile and about one live fish/mile were observed. Turbidity measurements were attempted with a very low budget approach. Spawning surveyors collected grab samples at established cross sections, but there were difficulties in relating stage to discharge and the sample size in individual tributaries was very small. Because of these problems, little can be concluded regarding turbidity. A schedule for re-evaluation of the 12 tributary reaches is included. It is suggested that parameters including LWD loading, channel cross-sections, and thalweg profiles be remeasured following geomorphically significant flood events, while other parameters such as water temperature, fish surveys, and turbidity be measured more frequently. To determine how forest practices are related to changes in channel conditions, addition of the BOF’s Hillslope Monitoring Program in the 12 study reaches of the Garcia River Instream Monitoring Project is recommended. Without this added component, the baseline may be used to determine whether channel conditions are trending toward target conditions, which would reflect on the Forest Practice Rules as a whole. But to connect impacts of timber operations, problems documented with hillslope monitoring need to be traced to channels. Without this understanding, it will be difficult to identify changes in the FPRs that are needed to prevent adverse impacts to downstream channels. Several recommendations for future cooperative projects are provided. These include: 1) utilizing hillslope monitoring in watersheds with instream monitoring reaches to relate upslope impacts to instream channel conditions, 2) gaining full landowner access prior to project implementation, 3), collecting data so that measurement units are comparable to numeric targets set by agencies, 4) defining an acceptable rate of change toward targets for selected parameters prior to instream monitoring—not after, 5) monitoring the fish themselves to estimate populations, and 6) providing more feedback to landowners regarding techniques and locations for controlling sediment entry.
Other Citation Details	Final report in KRIS bibliography as Maahs and Barber (2001). A GIS layer of survey reaches was digitized from the final report and is included in KRIS as the shapefile "grimpsites.shp". The following are the full citations for the WFPB (1995) and CDF (1988) papers cited above: WFPB (Washington Forest Practice Board). 1995. Board manual: Standard methodology for conducting watershed analysis. Version 3.0. November, 1995. Washington Department of Natural Resources, Olympia, WA. CDF (Calif. Department of Forestry). 1988. A guide to the wildlife habitats of California. K.E. Mayer and W.F. Laudenslayer, eds. Sacramento, CA. 166 p.
Contact Organization	O'Connor Environmental, Inc.
Contact Address	P.O. Box 794
Contact City	Healdsburg
Contact State	CA
Contact Zip Code	95448

 
 
 

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