U.S. Department of the Interior

U.S. Geological Survey

Low Steady Summer Flow

Synthesis Project

B. E. Ralston, M.E. Andersen SBSC/GCMRCReport to TWG Oct. 15, 2008

GCD Hydrograph fro

0

5000

100001500020000250003000035000

3/1/2000

4/1/2000

5/1/2000

6/1/2000

Discharge
Introduction & Backgro

 February 2000: Completion of Plan of E

Flows for Endangered Fish (SWCA 200

 April - September 2000: Implementation 

experimental hydrograph

 25 Studies initiated to evaluate flows o

biological and cultural resources

 August 2007: AMWG requested synthe

information
Hypotheses by Season 

Hydrograph

 Hydrograph designed 

around life history of native fishes

 Spawning in Spring Summer larval 

development

 Early fall exotic fish 

disturbance

GCD Hydrogra

0

5000

100001500020000250003000035000

3/1/2000

4/1/2000

5/1/2000

Discharge
Three Phase Approac

(Accelerated Schedule)

 Synopsis:

 Phase I. Summary of 

individual studies, Completed Summer 2008.

 Phase II. Workshop 

for secondary analysis 

 Aug. & Oct. 2008.

 Synthesis

 Phase II (c

and synthPublicatio

 Phase III. 

results of steady floJuly 09.
Current Status 2008

March – Initiated synopsis and data cons

through cooperative agreement with NoArizona University

July – Draft summary completedAugust – Workshop conducted: Physical 

resources

October – Workshop Held Oct 8th: Social 
General Conclusions Works

 Water temperatures in near shore 

most warmed by low volumes and sunlight; fluctuations of limited in

 Maximum young of year native fis

mouth of LCR observed at 13 kcfsat higher flows did not occur

 Flows greater than 8 kcfs appear 

threshold for exporting more san

Preliminary results, sub
General Conclusions Works

 New Zealand mudsnail numbers i

during 2000, but impacts to other observed

 Warm water appears to support a

diatom growth, but fluctuations cgrowth gains

 Chlodophora recovers quickly fol

disruption

Preliminary results, sub
General Conclusions Works

 Primary productivity and inverteb

Lees Ferry largely unaffected by t

 Lees Ferry rainbow trout appear t

successful reproduction in 2000; appears to have persisted for five 

 Tamarisk expanded initially in 200

persisted in only limited areas

Preliminary results, sub
General Conclusions Works

 Native sucker species and nonnative fa

minnows appear to have reproduced in 

 Humpback chub may have benefitted f

flows, but ageing is imperfect

 More campable areas available with sta Less time spent at off river attraction s

longer travel time

 Financial costs complicated by drough

California spot market prices in Summe

Preliminary results, sub
Aug. ’08 Workshop Outcom

 New USGS publication to be deve

FY09 (draft March 2009) – accelerschedule

 Executive Summary Experiment Overview/Introduction Synopsis (July ’08 - completed) Synthesizing results – augmenting k

assessment document and following Assessment format

 Recommendations for future studies
LSSF Workshop I and II Recommen

Further Description/Detailed ExplanAnalysis New Synthesis Topics:

 Quantify areal extent of warm near shore ha

with Thermal Infrared Data

 Quantify ponding at mouth of LCR Reanalyze fish capture data to clarify effect Synthesize fish and water temperature data 

more recent monitoring data)

 Vegetation effects on the ecosystem Use Bishop model to estimate willingness t

explanation of limitations of analysis.

 Look at AGFD creel survey to look at angle

2000.

 Incorporate safety and ability to learn over 

discussion.
Budget Summary

 FY 08: 100k FY 09: 80k

 40k carry over 40k new Sufficient for project