Water Collaborative Meeting Feb 11th

April 3, 2015 by CRC Action Group in News

CRCAG representatives were present at the Water Collaborative held on Feb 11, 2015. The detailed environment review ESRD request AMEC to perform for the McLean Creek Dam (MC1) was presented. A number of environmental, land use and social impacts were identified. A decision on whether the Province will proceed with the project will be announced some time in April. IBI presented its flood damage assessment for the City of Calgary.  Please refer to a previous CRCAG posting on Feb 27 regarding this assessment (http://protectcalgary.com/elbow-river-flood-mitigation-infrastructure-update/). CRCAG will also be meeting with IBI in the near future to obtain further insight into the analysis performed. TransAlta presented a brief update regarding potential operational changes for flood and drought mitigation. The summary of CRCAG’s meeting with ESRD on Feb 27 provides more detail than what was discussed at the Water Collaborative (http://protectcalgary.com/bow-river-update-and-call-to-action/). It is anticipated that an announcement for Bow River flood mitigation will be made soon. The 60+ responses WaterSMART received regarding its Room for the River Report has been forwarded to the Province for consideration. Further discussion involving the impact of forest management on hydrologic processes revealed that harvesting 20-30% of forests in a given watershed may lead to significant hydrologic disturbances. Further details and presentations from the meeting are included below.
McLean Creek (MC1) Dam Environmental Overview
MC1 is a dam on the main stem of the Elbow river that is designed to afford a 1:100 level of flood protection. AMEC was asked by ESRD to conduct a more detailed environmental review of MC1. They conducted a desktop review looking at issues involving water, land and social impacts, in addition to field work specific to the area which would contain the reservoir proper and within a 1km radius of the reservoir.

Water issues that were identified are seasonal flows, sediment loading, erosion, extent of inundation to adjacent land, the physical barrier of the dam itself and the impact on fish habitat, risk to the existing lake and river environment, the impact of Elbow Falls 10km upstream, impact on ground water and surface water quality, and wetlands in the area.

Land use and social impacts that were identified are the diverse range of terrestrial species in the area that will be impacted which are classified as either at risk, sensitive or may be at risk, the potential of rare plant species the high value placed on the existing environment, the requirement to move Hwy 66, the requirement of a historical resource impact assessment, and the necessity to assess cumulative impacts.

AMEC’s environmental review will be forwarded to the government for a decision as to whether it will proceed to the request for proposal and environmental impact assessment stages. It is anticipated that a decision will be announced sometime in April.
Cost Benefit Analysis – Provincial Flood Damage Assessment Study
IBI conducted a Provincial Flood Damage Assessment Study to update and develop flood damage curves in select communities at risk of flooding to 2014 economic values and establish adjustment indices for their use in different flood prone communities across Alberta, develop a computerized model for estimating flood damages and undertake flood damage estimates for select communities throughout Alberta, , specifically Calgary, High River, Ft. McMurray, and Drumheller. The Calgary assessment has been complete and a brief overview was provided. The study is now available online at http://alberta.ca/flood-mitigation-studies.cfm .

The assessment for Calgary built upon existing flood damage assessment studies (1986 Elbow River study and 1987 Bow River study). Flood damage curves were updated for residential and non-residential structures and their contents. A separate assessment was done for the Stampede.

Under the resulting “Flood Damage Database Management System”, a computerized model of damages likely to occur for all buildings (residential, commercial, infrastructural) at various flood levels, over 7200 buildings (approximately 5000 residential) were assessed against the damage curves established for the Model. The area caught by the Model would be the area of water inundation at the particular flood level plus a 75 meter perimeter. Different damage curves were assigned to different “classes” of buildings.

IBI strictly assessed tangible costs (versus intangible like psychological impact) associated with flood events ranging from 1:2 yr to 1:1000 yr. The Model estimated a total of $1.8B in damages is incurred in Calgary at the 1:100 flood level and $3B in damages at the 1:200 flood level.  These include what the Model defines as “direct” and “indirect” damages. From this “Average Annual Damages”, or damages avoided annually from having mitigation in place, equate to $84M on the Bow and Elbow rivers together.
Update from TransAlta
TransAlta and ESRD are looking at a comprehensive plan that will take into account flood and drought mitigation. For the short-term they will look towards changing operations at the Ghost Reservoir and will have something in place for the 2015 flood season. TransAlta is looking into the feasibility of lowering the Ghost below the 2014 pilot level of 1189.3m, however will need to determine if any further lowering will led to shoreline instability. TransAlta will be in a better position to come forward to the public with what they intend to do by the end of March.
Update from WaterSMART
WaterSMART received 60+ responses regarding the Room for the River Report. They will be compiling the responses in raw form, removing any identifiers, and forwarding the comments onto ESRD.  A revised Room for the River Report will be issued with this feedback attached. Reconfirmed that the Report is essentially a first review of the problems and possible responses, but are not policy statements or refined recommendations to Government. WaterSMART has been instructed by ESRD to conduct a second Room for the River pilot for the Red Deer River Basin, which will be completed sometime in May/June 2015.
Forest Management and Headwaters
ESRD forest hydrologist gave an overview of forest management in the Province and the impact deforestation may have on watershed hydrologic processes. The present models ESRD uses to determine the impact of deforestation on watershed hydrologic processes are adequate in predicting low flows, but are unable to address watershed-scale hydrologic processes such as peak flows and sediment loading and transport. ~20-30% of forests in a given watershed need to be harvested before a significant hydrologic disturbance is observed. Reforestation efforts will assist in hydrologic recovery and attenuate hydrologic disturbances due to forest harvest operations.