WA:TER


LIVING ON A FLOODPLAIN - AN OVERVIEW

WHY SALMON ARM NEEDS A FLOOD HAZARD AND RISK ASSESSMENT
[downloadable PDF version]

Extreme Weather

"Predicted changes in extremes include more record high temperatures; fewer but stronger tropical cyclones; wider areas of drought and increases in precipitation; increased climate variability; Arctic warming and attendant impacts; and continued sea level rise as greenhouse warming continues and even accelerates." (Credit: NOAA)

High River flood, June 2013
The 2013 Calgary flood was the result of heavy, sustained rain in the entire Bow River watershed west of Calgary: 226 mm of rain in 2.5 days, compared to the average June storm of 20 mm, accompanied by one meter of snowpack melt.
(Credit: John Pomeroy, Hydrologist, University of Saskatchewan - CBC, The National, 27 Sept 2013.)

High River flood, June 2013
"Boulder County (Colorado) was worst hit, with 9.08 inches (231 mm) recorded September 12 and up to 17 inches (430 mm) of rain recorded by September 15, [3][4][5] which is comparable to Boulder County's average annual precipitation (20.7 inches, 525 mm).[6]" High River flood, June 2013
Disastrous Consequences
Sicamous: Heavy rainfall. "It's washed out homes, it's taken homes off their foundations, it's washed out Waterways Houseboats' property - cars all over the place. It's just a mess." CBC News, 24 June 2012.

High River flood, June 2013
Toronto: "The storm and flash flooding that hit the GTA on July 8 has set a record for the Province's most expensive natural disaster, according to the Insurance Bureau of Canada."


High River flood, June 2013
Calgary: "Alberta homeowners hoping to make claims for flood damage won't get help for water that poured through doors or basement windows, the Insurance Bureau of Canada said Friday. 'You're not covered,' spokesman Steve Kee said. 'There's no overland flooding coverage in Canada.'"

"Worst natural disaster in Canada's history according to Insurance Bureau of Canada." Ian Hanomansing, CBC, The National, 27 Sept 2013.

PDF excerpts from Macleans, The Great Alberta Flood
High River flood, June 2013
"Colorado: ... affecting at least 1,918 square miles of the state and resulting in the likely deaths of 10 people and nearly $2 billion in property damage, offer a glimpse into the scope of devastation that this 1000-year storm brought down some Colorado communities."


High River flood, June 2013 High River flood, June 2013
Significance for Salmon Arm

Salmon Arm is not Sicamous, Toronto, Calgary or Boulder, but shares characteristics with each.
> At the end of a long, narrow valley in mountains with high snow packs.
> High, spring rainfall with simultaneous snow pack melt is fairly common and is expected to increase.
> Buildings, roads, bridges and the highway exist on the floodplain.
> An extreme flood would back up south of the highway and spread into town.
> To move from speculation to understanding can only occur with a flood hazard and risk study.
> The study would be a powerful aid in convincing the Province to redesign the highway and bridge.
Timeline
> Once funded, a hazard and risk study will take a year or two to contract and complete.
> Several more years will be required to develop appropriate policies and infra-structure plans.
> Additional years will be needed to raise funds for city infrastructure construction.
> Convincing the Province to redesign the highway and bridge, even with the study, could take years.
> Therefore, funding a flood hazard and risk study, soon, seems highly desirable.   top  home

High River flood, June 2013 High River flood, June 2013



FLOOD HAZARDS AT THE FOREFRONT

Salmon Arm Observer Editorial, July 16, 2013

"Given the situation of many of our southern Alberta neighbours, it is not surprising Salmon Arm city council will be taking another look at whether to push forward plans for flood hazard assessments of the Salmon River floodplain.

No doubt many communities in Canada will take a more critical look at building in flood zones. Already, criticism is being voiced that not enough attention was paid to the recommendations in a report following Alberta's 2005 flood.
High River flood, June 2013

Photo credit: Calgary Herald

One key recommendation was keeping up-to-date information on flood zones, as well as a restricting building development on flood-risk areas. The report stated that undeveloped flood plains are the natural and most effective form of flood mitigation possible.

The city previously designated a flood hazard assessment plan as a medium-range priority, which means a five-to-six-year wait before it would be scheduled. A suggestion this be moved forward into the short-term priorities was defeated at budget time, but it may be returning to the table.

Clearly, the sight of thousands of Albertan homes filled with water and debris, not to mention the huge cost involved with disaster relief for the thousands of displaced, is sparking a renewed interest in flood mitigation measures.

Prevention is clearly a less-expensive option that disaster relief or restoration, should a severe flooding event take place. It seems wise for local politicians to take a good, hard look at these priorities. Just ask an Albertan.
"

It is generally considered that a major flood event in Salmon Arm, although not predictable, is inevitable. For several years, flood experts, citizens and WA:TER have urged Salmon Arm city council to conduct a flood hazard and risk assessment, and cautioned against development that compromises the flood plain and/or takes away the possibility for proactive measures. The following articles, letters and images provide an overview of this work, and background information about flooding.
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Shuswap Lake high water - June 26, 2012
Shuswap Lake high water (June 26, 2012)
Photo credit: Ellen Atkin


Salmon River bridge
TCH bridge over Salmon River (May 22/11), Salmon Arm

THE RIVER DELTA AND FLOOD RISK

Movement of water through the river delta is a complex balance of give and take. Alter the balance and you alter flood risk and consequences. Many jurisdictions recognize their past mistakes and now manage river and floodplain development differently. Others mitigate damage as best they are able by attempting to rehabilitate normal river and floodplain function.

To better understand the Salmon River, floodplain and Shuswap Lake, WA:TER has gathered information from many sources. For those interested in greater detail, follow the links provided.


EVIDENCE FOR AN ACTIVE FLOODPLAIN
[ including 1st hand reports from the 1894 flood ]

SALMON RIVER FLOOD HAZARD
[ an overview of flood hazard indicators ]

FLOOD HAZARD PUBLIC MEETING
[ held March 15, 2011 in Salmon Arm ]

VIRTUAL DELTA WALK
[ a short video tour that doesn't require hip waders ]

FLOOD RISK ASSESSMENT NEEDED
[ CPR Engineering Services, Terratech Consulting, Streamworks Consulting, BC Rivers Consulting and Neskonlith Indian Band call for flood risk assessment ]

FLOOD HAZARD QUOTES
[ quotes drawn from the professional literature ]   top  home



THE 1984 SALMON ARM FLOOD


The pioneering Gordon family is well know to the Haney Heritage Society. WA:TER found letters held in the Atlantic Canada Virtual Archives between Annie Gordon, her sister Jessie, and their mother, that give fascinating first hand accounts of the 1894 flood.

" Salmon Arm, B.C. June 11th 1894
My Dear Mother,

Our bridge has been swept away by the flood, and there has been no traffic on the C.P.R. for over ten days. Ten miles of track has been completely destroyed and as much more under water east of Sicamous, so we have had no mail for some time, and I hardly know when this will go.
Annie Gordon letter from Annie Gordon to her mother in Pictou County
At Lulu Island, at the mouth of the Fraser River, the flood came on them suddenly, and the people could not get out of their houses. A steamer was sent for them from Westminster. Here in Salmon Arm a great deal of damage has been done, several farmers' crops entirely destroyed, and several flooded out of their houses. The water came within a foot of our door and we expected that we would have to turn out too, but the weather turned cold, and the water fell."   top  home

Gordon Salmon Valley cabin

aerial view to north

FISH HABITAT AS DEFINED BY ACTIVE FLOODING


The BC Ministry of Environment considers a floodplain to be active if it floods at least once every five years. This is an important distinction because only active floodplain is considered fish habitat, and when it comes to most land development, only fish habitat is covered by regulation. In 2008, the Salmon River delta was a single municipal council vote away from from large scale commercial development because it was reported by the developer that the delta did not flood *, and the Ministry of Environment and Salmon Arm City Council accepted this report. Since then the delta has been shown to flood more frequently than once every two years, unequivocally establishing it as critical fish habitat.
* August 2009 - Developer's report finds no evidence of active floodplain - "Within the project area, the Salmon River is contained within well defined banks and does not have alluvial deposits beyond the top-of-bank. Based on an active channel (geomorphological) assessment of the Salmon River, the river is migrating and therefore additional protection measures along the eastern and northeast sections of the property, where the river bends intersect the property, will be required to ensure the 30m SPEA remains intact." (SmartCentres' qualified environmental professional report, August 31, 2009, page 16)
flood patternRiver high water mark represented by orange line & lake high water mark by green line. Development overlay in this and following graphics represents the 2009 proposal.

flood pattern 1920'sThe above photo from the late 1920s shows somewhat different main river channel positions. It also shows Active Floodplain areas presently buried beneath landfill on the SW side of the property.   top  home

SCIENTIFIC EVIDENCE & OPINION IN SUPPORT OF AN ACTIVE FLOODPLAIN

1) SOIL CLASSIFICATION

"The soil within the "I 6 W" cottonwood forest area is a Gleyed Regosol (young mineral soil, permanently or periodically water saturated and oxygen-starved) derived from river flood (alluvial) deposits; it is moderately well to poorly drained, has mottles within 30 cm of the soil surface, and is subject to frequent flooding." (Salmon Arm soil mapping project, April 1979, BC Min. Env., Resource Analysis Branch, Kelowna, B.C.)

2) AGROLOGIST'S LOCAL EXPERIENCE

"Since the subject property is close to the mouth of Salmon River, the elevation of the land is somewhat lower and is subject to flooding during high water levels in late May to early June." (Bob Holtby, P.Ag. from "Holtby" report on removal of subject property from Agricultural Land Reserve, dated July 19, 2004)

3) SALMON RIVER DELTA LOCAL EXPERIENCE

"The river floods pretty much annually to the start of the Interpretive Trail at the Pit Houses on the west side, just downstream from the subject property." This observation correlates well with the high water mark of the active floodplain as observed at the nearby northwest corner of the subject property. (Louie Thomas, pers. comm. Dec. 2009, from a lifetime of experience at the Salmon River mouth area)

4) GEOLOGIC EVIDENCE

"... the delta is still very active, and very unpredictable". (Geologic Development of the Salmon River Delta by Dr. Murray Roed, GEOTERRAIN CONSULTANTS 4890 Westridge Drive, Kelowna, BC V1W 3A1)

5) ANECDOTAL HISTORICAL RECORDS
Ten years later in 1894 (after the CPR line was constructed in 1884/85), following an early and hot spring, "the lake level rose very high" according to the Centennial History of Salmon Arm, written by Ernest Doe in his 1971. Doe estimated about half of the Salmon Valley was under water, "The railway tracks from the Indian Reserve to Sinclair's farm were under water. The track then was a little lower and the fires in the small wood burning (train) engines were extinguished at every attempt to get through.", wrote Doe. Because the valley roads and rail line were flooded, Dairy Farmer A.J. Palmer had to row his full milk containers in a boat across the bay to "Slough Bridge" on the CPR line to ship it to Kamloops.
A note in the 1894 "Inland Sentinel" newspaper reported: "Salmon Arm crops are in a very precarious condition owing to the spring freshets; nearly the whole valley is flooded. Several of the settlers had to leave their homes last week." The newspaper also reported that valley bridges and culverts were washed away and wagon roads were flooded.
1894 ... Around May 29 after two weeks of warm weather, flooding was reported in Salmon Arm. Nearly the whole valley was flooded and several of the settlers had to leave their homes the previous week. James D. Gordon's bridge washed away and the government bridge on the road to Thos. Shaw's Ranch was expected to go shortly. The roads were flooded and the bridges and culverts were afloat. During the last week of May, following the rains of the previous week, warm weather prevailed in the Okanagan Valley and Upper Nicola. Up to that time, the weather had been very cool. Tappen Siding had reported "rain almost every day." Temperatures were between 80-90F (26.7-32.2C) in the shade. Early June the warm weather continued in the Interior. ... Around June 1 at Salmon Arm, nearly the whole valley was flooded. The previous week several of the settlers had to leave their homes because of the flooding.
6) WATER SURVEY CANADA ARCHIVED HYDROMETRIC DATA

The peak Shuswap Lake levels, measured at Canoe as metres above sea level (MASL), are shown on the following plot (red points). Also shown (blue points) on the horizontal axis, are the corresponding peak Salmon River cubic metres per second (CMS) flow rates, measured at the Trans Canada bridge over the river, for 1970 to 2008. The red line across the plot denotes the high water mark (HWM) for the lake as determined by the province, currently 348.7 MASL.

In each year a slight lag of the peak lake level behind the peak river flow can be seen. The peak lake level occurs on average 30 days after the peak river flow, although the lag times vary widely from year to year, ranging from 12 to 54 days. The following years had lag times of 15 days or less: 1972, 1981, 1985, 1990, 1996 and 2006. Also worth noting is that the contribution (input) of the Salmon River annually to the lake, at approximately 150 million cubic metres (CM) per year, is far less than those of the Shuswap River (approx. 2.8 billion CM per year), the Eagle River (approx. 1.3 billion CM per year), and the Adams River (approx. 6 billion CM per year). The plot shows that there is a clear link between the Salmon River's peak flows and the lake's peak levels. This, however, really implies that the Salmon River's flow behaviour at spring runoff is essentially the same as that of the Shuswap and Eagle, with the impact of the Adams runoff less clear. There is a suggestion from the blue flow points that flow rates for the Salmon River have been increasing during the 90's and beyond, although over the span of 41 years the upward trend is not statistically significant.

The highest lake level in this time span is seen in 1972. Eight out of the 41 years show peak levels above the 348.7 HWM. In 1972 the lake level peaked at 349.7 MASL, i.e. a metre above the HWM, and caused dramatic flooding. Even more widespread flooding occurred in 1948, with the most extensive flooding seen back in 1894. Extensive flooding may occur, e.g. in 1972, when peak level is very high, but peak flow is less dramatic. It may also occur, e.g. in 1997, when peak flow is very high, but peak level is less dramatic. This indicates that the interaction between the Salmon River's spring runoff and the rising levels of the lake during spring runoff is complex. It is clear that flooding of the river's delta and surrounding wetlands can occur not only from the river overtopping its banks, but also from the influx of the lake's water over a land area which has a trivial gradient or slope towards the lake. Additional complications are the damming effect of the CPR tracks across the delta and wetlands (there are only two exits for the river's runoff to escape to the lake, or for the lake's waters to flow onto the delta), and predicted significant increases in peak river flows caused by pine beetle devastation in the Salmon River watershed over the past 6-7 years. The complex interplay between spring river runoff flows and rising lake levels emphatically makes the point that thorough studies of this interplay - studies which have apparently never been carried out here - are critical in developing appropriate flood risk management strategies and insurance, and in guiding good development planning. lake levels and river peak flows 7) PHOTOGRAPHIC EVIDENCE
flood depositsRiver flood (alluvial) deposits. flood lichen linesLichen lines on trees result from frequent flooding.
active floodplainThis May 14, 1993 air photo shows the flood "foot print" of the Salmon River at its peak discharge volume for 1993 of 43.8 cubic meters per second. On that day the river's discharge volume was very near its five year average flood level. The B.C. Riparian Area Regulation sets the 1 in 5 year flood level "foot print" as the indicator of the extent of fish habitat. Much of the water-filled looping river oxbow area in the middle left side of the area, black line marked "subject property", was buried in land fill between September 1998 and September 2001, wiping out valuable fish habitat and functioning flood water dispersion channels. WA:TER believes that this oxbow area must be restored to its former condition.   top  home

water flows



SALMON RIVER FLOOD HAZARD

Park Mountain automated snow pillow gauge, is considered to be a good predictor of flooding potential within the South Thompson.

Flood warnings and advisories, and snow survey summaries and water supply bulletins can be found on the BC Forests, Lands and Natural Resource Operations River Forecast Centre website. A high streamflow advisory was issued for the Salmon River near Falkland May 11, 2011

The average temperature for April is a good indicator of flooding potential in the South Thompson area. Typically a below normal April temperature is a good indication of a higher than normal flood condition while an above normal April temperature is a good indicator of lower than normal flood potential. Average April temperatures at the Salmon Arm Airport were about 7.9 degrees. (National Climate Data and Information Archive)

A cool, early spring followed by either a hot spell and/or extended wet period in late May and/or early June can bring very high flood waters. Such conditions have been reported in 1913, 1928, 1948 and 1972 as well as more recently in 1996, 1997, 1999 and 2008. Lower than average stream and river level at the end of April are also a good indication of a higher than average flood potential. Real time river level information for the Salmon River can be found on the Environment Canada Water Office website.

Elevation map prepared from City of Salmon Arm LIDAR information. A printable version includes comments by professionals on where we are now and where we are headed, some costs of flooding, why floodplains are important and useful, and what we need to do next. (This is not a flood hazard map.)   top  home

LiDAR elevation map Salmon Arm



PUBLIC MEETING ON FLOOD HAZARD IN SALMON ARM

Listed below are video highlights of presentations made by a First Nations representative and three engineering professionals with flood risk expertise, at the public meeting sponsored by WA:TER, March 15, 2011.

1. Bonnie Thomas, President, Switzmalph Cultural Society
Presentation
2. Matthias Jakob, P.Geo., BGC Engineering
Presentation Introduction - Part I - Part II - Part III
3. Paul Doyle, P.Eng., BC Rivers Consulting
Presentation Part I - Part II
4. Alan Bates, P.Eng., Streamworks Consulting
Presentation
5. Questions from the floor -
  a)  Is it appropriate to use Aboriginal knowledge?
  b)  Are floodplain guidelines the law?
  c)  What guideline changes would you suggest?
  d)  How should bridges be designed?
  e)  Does lack of political will influence professionals?
  f)  How will increasing river flow affect the floodplain?

Flooding Mtg Poster
Summary comments by water resource professionals1 and Bonnie Thomas, Switzmalph Cultural Society2 president, at a public presentation hosted by WA:TER March 15, 2011

Presenters' Message

Rivers flood, sometimes drastically. The consequences, for people, can be devastating or beneficial. Devastation occurs, sooner or later, if people build on floodplains and restrict channel changes. Natural floodplains provide flood water storage, critical fish and wildlife habitat, rich soils, very productive vegetation, water purification and green space. European cities, with records of multiple drastic floods, are returning their channelized rivers back to a meandering state in order to reduce destructive flooding. The likelihood of drastic flooding of the Salmon River has increased due to beetle killed forests, logging, agriculture, development and weather change. The consequences are unknown, because no recent studies of likely flood levels exist. The provincially designated 200-year floodplain is seriously out of date. Many homes, businesses, the highway and CPR are at risk. Records of the floods of 1894, 1948 and 1972 provide some valuable insights. Consequently, a professional assessment of flood hazard and risk is recommended.

Some Details

First Nations Concerns
Neskonlith and Adams Lake Bands have not been included in decision making and consideration of possible hardships caused by floodplain development adjacent to Native land.
The importance of First Nations knowledge and their reliance on indigenous plants and wildlife appears to have been neglected by the local government.
The local government has not informed the provincial and federal governments of First Nations' concerns as the Local Government Act requires.
Flooding
Europeans recognize that attempting to protect properties by draining floodplains does not work. Natural benefits of meandering rivers and associated wetlands are impaired or lost. Water quality declines when rivers are altered.
Efforts to channelize rivers do not work; much of Alan Bates' work is restoring river channels to their condition before being modified by man.
Flood hazards increase as homes and other developments are allowed on floodplains.
In North America, accurate records for 200-year and longer durations do not exist, so predictions of flood hazards are unreliable.
Flooding Mtg Poster
The currently used 200-year-floodplain is out of date due to beetle killed forests, development, agriculture, logging and weather change.
Local governments have had responsibility for land use planning and development since 1974. Some have created by-laws to deal with flood hazard and risk, but many have not.
The Salmon River floodplain is classified as hazardous and active due to frequent channel changes.
The 1894 flood was much greater than that of 1972 [adjacent photograph from GeoTour Guide for Kamloops, Geological Survey of Canada Open File 5810]. Development on floodplains has always been controversial.
Ecology
Spring, Sockeye and Coho Salmon habitat needs to be protected, if population recoveries are to occur.
Leaving wetlands and fish habitat in a natural condition will protect Shuswap Lake water quality.
Filling wetlands influences their filtration function and changes groundwater flow. Even logging roads through wetlands result in flood death on one side and drought death on the other.
1 Dr. Matthias Jakob, P.Geo., of BGC Engineering, Paul Doyle, P.Eng., of BC Rivers Consulting and Alan Bates, P.Eng., of Streamworks Consulting.
2 The non-profit organization seeking to implement Dr. Mary Thomas' vision.


Salmon Arm Observer coverage of March 15, 2011 public presentation

EXAMINING FLOOD RISK

By Martha Wickett - Salmon Arm Observer March 30, 2011

It's time to reconsider flood levels of the Salmon River in case the area experiences, sooner than later, a flood like that in 1894.

This was one of the messages carried by water resource specialists who spoke in Salmon Arm regarding rivers, flooding and the Salmon River delta.

Paul Doyle, a hydrotechnical engineer, told the Observer the Salmon River delta is a complicated hydrologic situation because of several factors. Among them are the limited openings in the highway embankment where the bridge is, and in the railway embankment where the two rail bridges are.

"Partial obstruction of flows in the Salmon River are certainly more likely to occur when you have those limited openings in both those embankments," he said, noting partial plugging of the waterway openings can occur when the river deposits material, sometimes trees, during high flow. There's also the fact the lake level is what controls the water levels back as you go upstream on the river, plus the river has been altered in some spots by berms and dikes.

Then there's climate change.

"A lot of people brush that off. It's happening, it's real, it's going to get a lot worse and it's happening faster," Doyle said. Considering all the factors together, "those are the main things people can't tie down no matter how smart or knowledgeable they think they are."

Doyle would like to see a re-investigation of the flood-plain mapping done in 1990, given that stream flows over the past 20 years have shown changes, and mapping techniques have improved.

"What's particularly unsettling to me, we've seen '72 and '48 (floods in those years), but the 1894 flood is poorly documented," he said, noting it dwarfed any seen since. "People think '48 and '72 were pretty big events in the region and on the Salmon (River) but they were nothing like it could be."

As a person who studies such events, he says, "Wild thing happen when there's an extreme flood that people don't even think about. I can assure people strange things can happen; it's not to anybody's benefit when you get a big flood."

Alan Bates is a river engineer from Salmon Arm whose area of expertise is river restoration, working mainly in the Southern Interior and the Kootenays.

"If you can give a river space to do what it needs to do, it's a lot better. Anytime you start crowding them..., the more you squeeze it, the more it fights back. That's a simplification, but that's what they've learned in Europe," Bates said.

Rather than have a town sit on a river, he said, farmers' fields, hiking trails and playgrounds are better alternatives for a floodplain.

"When the flood comes, you can say, 'Oh well, we haven't lost a lot of infrastructure."

Referring specifically to the Salmon River delta, he said it helps protect the water quality of Shuswap Lake.

"They build water treatment plants to mimic wetlands," he continued, noting that debris, sediment and nutrients come down in a flood, which the delta processes.

Measuring how high a river floods is only one issue to consider," he said. "If building occurs on a floodplain, then what would have been processed by the delta may be forced out into the lake. If too much building occurs, diking and dredging will have to take place.

"If you leave it natural, it takes care of itself."

His wish, as a Salmon Arm resident, is that he never has to restore anything in the Salmon River floodplain or delta.

The engineers spoke as part of a meeting hosted by Wa:ter, (Wetland Alliance: The Ecological Response), to provide information about water movement in the Salmon River delta. It is a topic the group has been pushing to have studied, particularly because of plans to build a shopping centre adjacent to the river.
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FLOOD RISK ASSESSMENT NEEDED


Canadian Pacific Railway, Neskonlith Indian Band (see SA Observer article "City Expecting Response"), Streamworks Consulting, BC Rivers Consulting and WA:TER (see March 15, 2011 public flood risk presentation) have urged the City of Salmon Arm to engage the services of a recognized consulting engineer with expertise in surface water hydrology and fluvial geomorphology to assess flood risk in Salmon Arm.

TERRATECH CONSULTING REQUESTS FLOOD RISK ASSESSMENT - November & December, 2010

On February 6, 2012, Calvin van Buskirk, from Terratech Consulting, made a presentation to Salmon Arm Mayor and Council on the need for a flood risk assessment to guide the City's long term planning. A second presentation on the same topic, at a WA:TER hosted public meeting on February 16, 2012, can be viewed by clicking the following links. These presentations follow a written submission in December 2010.

TERRATECH PRESENTATION: Introduction, Part 1, Part 2, Part 3, Part 4, Part 5

December 21, 2010
To: Mayor and Council, City of Salmon Arm

As the fourth reading for the proposed rezoning of property located within the active portion of the Salmon River delta has now been held, I am writing to inform you of correspondence I have had with City staff over the past two months regarding the City's management of flood prone areas.

The first attachment is an email to Dale McTaggart and includes a copy of a letter sent to Corey Paiement dated 9 November 2010.
The second attachment is a follow-up e-mail to Dale McTaggart which includes an attachment titled "Flood Hazard Area Land Use Management Guidelines".
The third is an e-mail to Corey Paiement and Dale McTaggart regarding the value of and risk posed to Urban Wetlands.
The fourth is an article from the Association of Professional Engineers and Geoscientists regarding Flood Hazard and Risk Assessment.
The fifth is the City's response to the 9 November letter.
The sixth attachment is a brief description of deltas.

Based on the attached, I would like to draw your attention to the following facts as I see them:
1.   Neither the City nor the Developer have publicly acknowledged that either party has any technical knowledge about the function or dynamics of the Salmon River Delta (this was made clear by 2 through 6 below).
2.   The City encouraged the development of the subject site by supporting its removal from the agricultural land reserve.
3.   The City, through contracts, direct or indirect, with local earthworks contractors contributed to the deposition of fill within the floodwater channel(s) on the subject site.
4.   The City did not request that the developers provide either a flood hazard or flood risk assessment to support their application for rezoning.
5.   The City did not request an environmental impact assessment with respect to the proposed development.
6.   The developer hired two professional biologists to assess the 1 in 5 year flood level for the Salmon River rather than a fluvial geomorphologist. The developer continued working with the biologists even after serious mistakes were made in the first RAR report.
7.   According to the Provincial Government, the City has the authority to request any studies it feels are necessary to support an application for rezoning of land.
8.   The City's approach to managing flood hazard and risk does not meet the recommended minimum requirements as outlined in the attached provincial government "Flood Hazard Area Land Use Management Guidelines" that were prepared in support of the transfer of this authority to the City.
9.   The "Flood Hazard Area Land Use Management Guidelines" would not have permitted the infilling of the flood channels on the subject property.
10.   The existing fill material cannot be safely built upon and must be removed along with the underlying topsoil (this requirement is included within the geotechnical report provided by the developers).
11.   Although the guideline being prepared by APEGBC does not currently form Best Management Practices as it has not been released, much of the content of the document as included in the attached "Flood Risk Assessments in Canada" article would currently be considered as a standard of practice. In addition, the "Flood Hazard Area Land Use Management Guidelines" would form part of the current standard of practice.
12.   The 200 year flood design discharge of about 59 cubic metres per second used in the 1990 study that produced the current floodplain mapping for the Salmon River was reached in 1996 and 1997. Given this, plus the additional 20 years of data now available, the floodplain mapping and current elevations used to support development within the Salmon River area are clearly out of date and should be reviewed and revised.
13.   The placement of fill is not regulated within the City of Salmon Arm even though many other Cities and Municipalities recognize the importance of regulating fill placement from the perspective of responsible land use management. The lack of regulation permits irresponsible fill placement that can lead to flooding, landslides, sedimentation and environmental damage. Within BC, Canada and around the world, the cost of lessons learned in terms of economic losses, environmental losses and the loss of life have been staggering.

I would like to request that the Mayor and Council consider the above and attached information and provide appropriate instruction to the City staff such that development within or adjacent to flood-prone areas is undertaken in a responsible manner that acknowledges and safeguards the interests of all stakeholders.

In addition, I would request that the City's approach to management of flood-prone areas and the regulation of fill removal and fill placement be updated to safeguard the public and limit the potential for financial losses and environmental damage.

In closing, I would like to state that I am not against development in Salmon Arm or even at this site, however, in my professional opinion, permanently infilling an active flood channel without knowledge of the implications of such actions does not make any sense. That said, it should be possible to reconfigure the proposed development to reinstate the flood channel and still provide the size of development requested by the developer. By exploring such opportunities, I feel a significant amount of the strong opposition to this development, which has divided our community, could be put to rest.

I look forward to a response from the Mayor and Council.

If you have any questions or comments, please contact me.

Yours truly
Terratech Consulting Ltd.
Calvin VanBuskirk, P.Eng., FEC, P.Geo.

PS. For those who are not familiar with Terratech Consulting, we have been in business in Salmon Arm since 1988 and have donated several thousands of dollars in materials, design and consulting services to community projects including: the waterfront Gazebo; Greenways; Shuswap Trail Alliance and the Haney Heritage Park Bridge over Canoe Creek.

Attachments:   City of Salmon Arm reply, flood risk assessment, BC flood hazard area guidelines, delta definitions

CPR ENGINEERING SERVICES REQUESTS FLOOD RISK ASSESSMENT - December 15, 2010

Five days before Council passed 4th reading for the SmartCentres development proposal for the Salmon River floodplain, Canadian Pacific Railway (CPR) wrote
"requesting that the City of Salmon Arm either retain directly or require that the proponent retain the services of a recognized consulting engineer with expertise in surface water hydrology and fluvial geomorphology to assess the changes in flood risk introduced by the existing and proposed fill and development within the SmartCentres property. The existing fill and the proposed fill are within the jurisdiction of the City of Salmon Arm and therefore the CPR relies on the City to ensure that adequate safety consideration are preserved as per the Railway Safety Act of Canada (Part III, Section 24c). CPR is specifically concerned that the existing and proposed fill will direct more flow to the CPR Mile 64.60 bridge [Salmon River] compared to the current condition. Currently during extreme flood conditions the Salmon River over tops its banks and flows through both bridges."
Excerpt from Dec. 15/10 CPR letter (pages 1 & 2).


CITY EXPECTING RESPONSE FROM SMARTCENTRES

By Martha Wickett - Salmon Arm Observer Published: June 28, 2011 6:00 PM

Calls for a flood risk assessment of the Salmon River delta before development occurs on the site is expected to prompt a response from SmartCentres.

The Neskonlith Indian Band wrote to the City of Salmon Arm on June 3, reiterating its concerns about flooding and explaining that its legal counsel had retained an expert, Prof. Michael Church, to determine if flood risk was being properly assessed for the proposed shopping centre.

Church states in his report there's a consistent trend of increasing flows in the Salmon River, and the development in the form currently proposed doesn't meet criteria to be above flood construction level. He recommends the flood profile be reanalyzed using current data and the flood hazard be reassessed.

"If the development was to proceed in its current form it is expected to flood in the near future," states the letter from the Neskonlith to the city. "This would result in the implementation of flood mitigation measures, which in turn could have a significant impact on neighbouring ecological values and adjacent properties, including the Neskonlith Indian Reserve Lands."

Mayor Marty Bootsma told the Observer Friday that Corey Paiement, the city's director of development and planning services, is going over the Church report and he thinks he has asked SmartCentres to prepare a response. "It's a wait and see," said Bootsma. "We'll see their response."

He noted that the environmentally hazardous area development permit application is expected to come to council shortly.

"We'll get the reports and staff input on it, and go from there."

Paiement stated Friday that SmartCentres is providing a response but the city hasn't yet received it.

On June 17, the Observer asked Carl Bannister, the city's chief administrative officer, what the city's approach to flood assessment is, given that the province in 2004 downloaded the responsibility for flood hazard area land-use management to local governments.

He said a flood hazard assessment of the delta is not currently being planned.

"We don't have any plans at this point and have not been given any direction from council to do any broad study of the Salmon River delta," he said, confirming that the city has received the Church report as well as the Matthias Jakob report commissioned by the Wa:ter group and is reviewing them, as are SmartCentres engineers.

"If there's a disagreement between professional engineers, that's something they need to sort out amongst themselves within their own association."

He said staff are reviewing all reports in view of local, provincial and federal regulations.

"If we have concerns that none of those are being met, we'll go from there."
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FLOOD HAZARD QUOTES

Gilbert F. White: "The great tragedy of Katrina is that the hard lessons learned in ... earlier storms were blithely forgotten by all. After the great Mississippi River flood of 1927 wreaked havoc all along its course and came within a few feet of spilling over the river levees and inundating New Orleans, the growing city clamored for additional protection. Over the coming decades, the federal government erected a vast network of levees and spillways along the river and around the city, while giant new dams along the Missouri - the Mississippi's longest tributary - ponded water all the way to South Dakota. The system was billed as a triumph of engineering over nature. Yet Gilbert F. White, considered the "father of floodplain management", came to a far different conclusion, one that Katrina drove home with a vengeance. As a young University of Chicago geographer, White had studied the delta after the 1927 disaster and realized that much of the suffering could have been avoided. "Floods are 'acts of God,' " he wrote in 1942, "but flood losses are largely acts of man." White and his colleagues argued that dams, levees, and other flood protections may actually increase flood losses because they spur new development in the floodplain, which incurs catastrophic losses when man-made flood protections fail. The phenomenon came to be known as the "levee effect." (National Geographic)   top  home