North Poudre Sediment Study Work Plan

• Project Type: Ag/Muni Grant
• Applicant: North Poudre Irrigation Company
• Project Name: North Fork Poudre Sedimentation Study
• Title: Work Plan, Schedule and Outcomes
• Date: 6/9/1997
• County: Larimer
• Water Conservation - Doc Type: Work Plan

,/

~~M,;i- A _
-

Work Plan. Schedule. and Outcomes

I) Field work: The primary objective is to create a data base that can be used to calibrateltest
sediment transport models. This data base will consist of velocity and sediment transport
measurements, and of repeat surveys of study reaches to measure pool scour or aggradation
following high flows. We have established two sediment and velocity sample cross sections,
500 m and 3 km downstream from the dam, respectively. We also have 3 survey reaches;
500 m, 3 km, and 5 km downstream from the dam, respectively.

Initial survey: 12 October 1996
Repeat survey: 31 March 1997
(anticipated; 1 August 1997)

Sampling velocity, suspended and bedload sediment:

26 November 1996
22 February 1997
24 February
2 March
5 March
13 March
19 March
23 March
8 April
15 April
19 April
22 April

Sample times have largely been dictated by fluctuating flow releases from Halligan
Reservoir. We will continue sampling through the end of the 1997 high flow (June or July).
Funds requested in the original proposal will be used for salary of the student conducting the
modeling, and to reimburse field expenses incurred after the research contract is signed.

I
2) Sediment transport model calibration: A PhD student (Sara Rathburn) who is familiar with
the use of HEC-6 will begin using the field data to test the sediment transport models in May
1997. Sara will be testing the models through the summer of 1997 and the academic year of
1997-98. A preliminary progress report summarizing field data and initial model results will
be ready by December 1, 1997.

By May I, 1998 we will be able to report on the accuracy of the HEC-6, G*, and Milhous
models, as detailed in the original proposal, relative to field observations on the North Fork
Poudre River. This report will include the original field data and the model outputs, with an
assessment of the merits and shortcomings of each model. The report will also include;

(1) discussion of feasibility of model use by water resource managers (Le., ease of model use,
required data input, details of model output),