Pierre River Mine Project

WATER AENV SIRS 15 – 43
Question No. 21
Request Volume 2, SIR 288, Page 21-39.
Section 12.1
Shell states that streams outside the disturbance footprint will have a 100-m
setback distance.
21a Clarify if ephemeral watercourses were considered and included in this setback
criterion.
Response 21a As per the response to the May 2009 Pierre River Mine, Supplemental
Information, Volume 2, SIR 288, a 100 m setback will be maintained for streams
around the periphery of the disturbance footprint. For this project, these streams
are limited to constructed diversion channels adjacent to the main Pierre River
Mine footprint, such as the Pierre River diversion, which would maintain the 100
m setback. Ephemeral watercourses were considered because ephemeral streams
located around the periphery of the project footprint would be directed into the
diversion channels, which will have the 100 m setback.
Question No. 22
Request Volume 2, SIR 289a, Page 21-40.
Shell states that the Actual Evapotranspiration (AET) is estimated based on
actual evapotranspiration simulated for natural areas using the Hydrologic
Simulation Program Fortran (HSPF) model. The HSPF model determines an
estimated AET based on an estimate of PET (potential evapotranspiration) and
five other primary factors (HSPF subroutines). It is not clear how Shell
estimated AET based on a simulated AET without first having PET estimates,
accurate and reliable water storage values, and an adjustment for advective
winds.
22a Briefly describe the steps that provided input data, estimated PET, and
calculated AET.
Response 22a The steps used to estimate potential evapotranspiration (PET) using Morton’s
evaporation model and actual evapotranspiration (AET) using HSPF, and the
input data required for these models are as follows:
• Morton’s Evaporation model is used to determine Potential
Evapotranspiration (PET), areal actual evapotranspiration, potential lake
evaporation (PE), and actual lake evaporation. The input to Morton’s
Evaporation model includes mean annual precipitation, monthly mean wind
speed, monthly mean relative humidity or dew point temperature, and
monthly mean solar radiation data recorded at the Fort McMurray Airport
climate station from 1954 to 2006.
April 2010 Shell Canada Limited 12-23
CR029