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Sample Design: Lemhi Watershed Habitat Surveys (Pratt Creek) within the Columbia Habitat Monitoring Program (CHaMP) in 2014

Study Design: CHaMP - Lemhi Watershed Habitat Monitoring Scientific Protocol for Salmonid Habitat Surveys within the Columbia Habitat Monitoring Program (CHaMP) v4.0

Sample Design: Lemhi Watershed Habitat Surveys (Pratt Creek) within the Columbia Habitat Monitoring Program (CHaMP) in 2014
ID: 360
State: Finalized
  • State: Finalized
  • Owner: Carol Volk
  • Spatial Design Category: Generalized Random Tessellation Stratified (GRTS)
  • Data Repository:
  • Snapshot: 5/13/2014
  • Snapshot by: Carol Volk
  • Sites in Design: 8
  • Has Location Privacy: No

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The details of this Sample Design, including all the parameters used to generate it, are included below. Sample designs must belong to a Study Design.


CHaMP is designed as a Columbia River basin-wide habitat status and trends monitoring program built around a single protocol with a programmatic approach to data collection and management (RM&E Workgroup 2010). CHaMP will result in the collection and analysis of systematic habitat status and trends information that will be used to assess basin-wide habitat conditions. When coupled with biological response indicators, this status and trends information will be used to evaluate habitat management strategies. This program will be integrated with ongoing Pacific Northwest Aquatic Monitoring Program (PNAMP) recovery planning efforts and will be part of the collaborative process across Columbia Basin fish management agencies and tribes and other state and federal agencies that are monitoring anadromous salmonids and/or their habitat. The implementation of CHaMP will characterize stream responses to watershed restoration and/or management actions in at least one population within each steelhead and spring Chinook Major Population Group (MPG) which have, or will have, “fish-in” and “fish-out” monitoring (identified in RPA 50.6), thereby meeting the requirements of RPA 56.3, RPA 57, and RPA 3. CHaMP was designed to deliver trends in habitat indicators and requires that monitoring occurs for three cycles of a sampling panel (see section 1.6), at least 9 years.

Lemhi’s primary objective was to estimate habitat condition for the Lemhi subbasin, and estimate the habitat condition in the priority drainages (see strata list). The Lemhi status and trends sampling design consisted of 45 unique sites sampled over three years (the standard CHaMP design) and was supplemented with 72 sites funded by the ISEMP program until 2013.  The Steelhead (Snake River Basin DPS) - Lemhi River and  the Chinook Salmon (Snake River Spring/Summer-run ESU) - Lemhi River were the populations of interest.  The original rationale was to allocate annual sites across the smaller tributaries to get a broad coverage of the diversity of habitat types, and use more rotating panel sites in the larger tributaries. 

In 2014, habitat restoration efforts planned for the Lemhi River include the removal of barriers on Lee and Pratt Creeks, enabling year-around access for anadromous fish and opening the Lemhi CHaMP target frame to these areas.  This design is a supplemental GRTS draw for the Lemhi 2011-2013 CHaMP design within the anadromous area of Pratt Creek.  One site in each of 3 rotating panels will be drawn using GRTS.  An Extra panel will include the oversample sites available for all panels due to the small target frame and limited number of master sample sites. 

In 2015, there were no updates to the Pratt design.  The Lemhi Status and Trend design (ID 420) was updated to accommodate 10% repeat sampling in 2015, but the Pratt Creek stratum was not impacted.

Sample Design Parameters

Start Year


Study Design

CHaMP - Lemhi Watershed Habitat Monitoring Scientific Protocol for Salmonid Habitat Surveys within the Columbia Habitat Monitoring Program (CHaMP) v4.0





Map of Sites

Stratum Panel Occasion

Area of Inference


AOI Notes


This sample design is based on master sample: Columbia Basin Master Sample

Details of this master sample:


This sample design started with an initial frame of 551,046 sites, based on its master sample. The criteria (based on the master sample's attributes) were then used to refine the sample frame down to 8 sites:

Criteria Group 1
  Trib Is Equal To Pratt

Target Population

Pratt Creek addition to the Lemhi design was defined by QCI.  Sampling extends to IDFG extent of O. mykiss capture, which is LCPC-6. The last site of IDFG O. mykiss capture is LSPC-5.  Note that there is a short section of Lower Sandy Creek that connects Pratt Creek to the Lemhi, and this is included in the Pratt design.   

Panel designs can help address sampling objectives by increasing the total number of samples at a lower overall cost. A common panel structure involves one or more panels with a high revisit frequency (e.g. an “Annual” panel), and other panels with a lower revisit frequency (e.g. a three year “Rotating” panel).

Panel Sampling Occasion (9 Year(s))
# Panel Name Panel Abbr. 1 2 3 4 5 6 7 8 9
Rotating Panel 1
Rotating Panel 2
Rotating Panel 3

This design uses the following attributes to create the stratification shown below. Each row in the table represents a stratum. This design’s panels are also shown in the table, even if it uses only a single, default panel.

Sample Attributes
  Attribute   Values In Frame
  Trib 1 Value: Pratt
Attributes # Sites In Frame Frame Length (km) Stratum Attributes Panels
Trib Stratum Name Stratum Abbr. Rotating Panel 1 Rotating Panel 2 Rotating Panel 3 Extra # of Sites
Pratt 8 10.4 Pratt Pratt 1 1 1 5
TOTAL 10.4 km      

Below is the complete list of sample sites that were drawn using the criteria for this sample design.

Number of sites before generating the GRTS sample: 8
Number of sites after generating the GRTS sample: 8
Number of oversamples: 0
Number of panels: 4
Number of strata: 1




The histogram charts below show the distribution of this sample design’s sites across the various panels and strata.


  Schema   Attribute   Description