Showing posts with label overland flood endorsement. Show all posts
Showing posts with label overland flood endorsement. Show all posts

Canadian Flood Underwriter - Can Fire Underwriters Survey History Guide Urban Flood Risk Management Model?

Can the history of the Fire Underwriter Survey provide a roadmap to a future Canadian flood underwriting model?

Fire Underwriters Survey (FUS) is a national organization and was formerly the Insurers’ Advisory Organization (IAO) and Canadian Underwriters Association. As noted on their site, "FUS provides data on public fire protection for fire insurance statistical work and underwriting purposes of subscribing insurance companies. Subscribers of Fire Underwriters Survey represent approximately 85 percent of the private sector property and casualty insurers in Canada."

The history of the FUA and the organizational and technical benefits offered to its members is described in this book:


"The Underwriters, the history of the Insurers' Advisory Organization and its predecessors, the Canadian Fire Underwriters' Association and the Canadian Underwriters' Association," by Christopher L. Hives, 1985.

If "flood is the new fire" as far as Canadian insurance losses go (Fort McMurray 2016 notwithstanding), much can be learned in how the insurance industry developed the Fire Underwriters organization to organize, guide, educate, and support member insurance companies.

How did fire insurance evolve?

The first fire policy was written by the Phoenix Company in 1782 policy in Sr. John's, Newfoundland and the first Canadian company to offer fire insurance was the Nova Scotia Fire Insurance Association, founded in 1809 in Halifax. More players joined and by the mid 1800's it was apparent there was a need for standardization and organization - so in 1857 "in order to better serve the interests of the community and the participating companies, a joint body or association called the Halifax Insurance Board (was) formed".

Following a 1859 severe fire in downtown Halifax with payouts of £128,075 the board commented on causes and identified "the want of sufficient supply of water at the commencement and to a general want of management". It made recommendations for an improved city water supply for the city, more firemen, and water supply infrastructure along Barrack Street with branch lines exclusively for fires. Without these risk reduction measures, the board would increase tariffs (i.e., premiums).

The early Halifax example illustrates the partnership between government and insurance industry whereby standards for municipal services consider insurance industry needs, which it could be argued, mirror the financial needs of the economy, and the government's need to promote safety and security in the community as a whole.

Over the next century or so, a national organization was formed, evolved and grew (Canadian Underwriter's Association (CUA) founded in the late 1880's, and Insurer's Advisory Organization (IAO) in the 1970's incorporating CUA and independent members). In the late 1970s, lAO developed one of its first computer applications to determine whether a sprinkler system would function properly and if the water supply was sufficient. This replaced inefficient manual calculations.

One could draw parallels between the IAO's analysis of sprinkler fire suppression systems and the assessed benefits of flood prevention systems. In the case of large watersheds in the Toronto area, prevention features would include infrastructure such as the Lower Donlands Landform Berm, Black Creek Channel, and TRCA dams - all incorporated in JBA's flood defense layers. At the local municipal level, flood prevention features would include drainage and municipal infrastructure standards incorporated in new resilient communities, or upgrades for flood risk mitigation in communities build with lower standards (e.g., pre-1980's subdivisions with limited overland drainage design, and partially-separated wastewater systems).

Currently CGI Risk Management Services conducts  Fire Underwriters Survey (FUS) services for the Canadian insurance industry, including assessment of municipal water supply systems including adequacy of available flow rates for structures in the community, and distribution system adequacy and reliability. This information helps guide community improvements and to establish "municipal gradings for insurance purposes", according to CGI.  

The parallel in the context of urban flood risk assessment would be i) assessment of wastewater systems to safety convey extraneous flows during extreme wet weather events, without surcharging and causing floor drain sewer back-up, and ii) assessment of overland drainage systems to safely convey overland runoff ('major drainage system flows) to an adequate outlet like a channel or valley, without surrounding and entering buildings. Since the 1970's, computer assessments of wastewater system capacity has been pursued using the SWMM model, typically in the context of flood remediation or CSO reduction studies. Today, such models are more widely available, but even in jurisdictions like Toronto, they are only now being developed to cover the entire municipality and to be developed with robust standards. Over time, the risk characterization from such models could be used to establish a municipal grading for insurance purposes, likely at a block face level of detail. Overland flood risk models are only now becoming commonplace, including JBA's riverine and surface (pluvial) flood risk models based on 2D overland flow modelling. 

The difference between CGI's fire risk assessments and flood risk assessments is that no flood risk assessments are tied to 'municipal gradings'. Municipal wastewater system assessments can result in infrastructure improvements, or when not cost effective, deferred projects. But neither condition is communicated to an insurance risk body, and the insurance industry is not known to participate as a stakeholder in the municipal environmental assessment studies that guide the improvement strategies. Similarly, the overland risk assessment available to those writing individual policies are not shared with municipalities to guide macro-scale, neighbourhood-level improvements to infrastructure that could mitigate risks and premiums. IBC's Municipal Risk Assessment Tool (MRAT) estimates municipal wastewater back-up risks but these are not used to set premium rates or identify specific municipal infrastructure improvements (i.e., MRAT provides generalized, regression-based "high-low" risk mapping for one type of flood risk but does not incorporate system hydraulics to assess upgrades, nor does it assess neighbourhood overland flood risks or remediations).

Given that fire insurance and underwriting support evolved over more than 200 years, and that technical assessments of some risk factors like fire suppression sprinklers emerged only 40 years ago, flood risk underwriting likely has decades to go before an effective partnership can develop between the insurance industry and municipalities and other levels of government.

"...our industry will undergo fundamental and radical changes which will severely test the mettle of all the players in the league. 'To be sure, the 'good old days' are gone forever. Today's conditions, regarded by many as 'abnormal' are, in reality, 'but a mild rain shower compared to the storms of the future ...obviously, the future is no place for the faintheaded, the rigid traditionalists and the seekers of the status quo. The survivors will be the courageous, the alert, the flexible, the imaginative,
the planners and the managers of change. With the continued support of its Members, lAO would like to be counted among the latter."
Ted Belton's comments on the status ofthe industry at the end of 1980, following all time high 1980/1981 loss ratios.

Given current flood loss trends, Mr. Belton could have been looking out 35 years to today when investment earnings are low (again) in this low interest environment, and when extreme rainfall losses are on the rise. Imaginative change is again needed to develop a flood underwriting strategy.

Overland Flood Risk - From Flood Plains to Foundation Drains

From foundation drain to floodplain there is a continuum of drainage features that affect flood risks and damages in urban areas - these are micro lot level factors and macro neighbourhood factors.
River flood risks are defined by floodplain maps (called
engineered floodplains) because of the detailed hydrologic
analysis used to define flood flows and river and bridge
surveys used to define river and valley hydraulics to define
precise flood levels. Hazards in these zones are closely
regulated, new development is not permitted, and
 redevelopment is subject to special policies if allowed.

Yes, some property reference points could identify a few flood risk factors to address, but overland flooding risk is not apparent at the property scale - that is if we agree overland flooding is not a result of poor lot grading or obvious rain entry points.  Unlike other risks like fire hazards, the structure or property does not define most of the risk when if comes to flooding. It will be interesting to see what methods Aviva has adopted for defining risk levels and overland flood endorsement premiums.

Aviva is excluding high risk properties (about 5% of properties) considering flood plain maps that identify river (and sometimes lake) flooding hazards. Micro-scale factors like the property's foundation drain and service lateral condition can affect almost any property, but issues with those do not cause overland / surface water flooding.

Overland flow areas in an urban setting.  Areas beyond blue
regulated floodplains may be several hundred hectares in size.
I'd suggest the most sensitive overland flooding occurs upstream of large floodplain-mapped valleys and up onto urbanized 'table land' where the sewer drainage system and overland drainage system are not designed to accommodate runoff from major rainfall events.  Usually this would be in catchments draining a 125 hectare or smaller area in Ontario, lying beyond the regulated flood zones above where Aviva insurance would not be available. In these areas, neither the capacity of the storm sewer system, nor the adequacy of the overland drainage system (ideally on roadways and drainage easements) is apparent at the individual property scale.

The macro-scale, overland system is only apparent from runoff accumulation and concentration from 10's of hectares to even a couple hundred hectares of table land runoff that accumulates downstream. That is, a broad neighbourhood-scale macro factor representing many hundreds upstream of properties. The map of overland flow drainage areas (red text in yellow highlight) shows the continuum of drainage areas extending beyond regulated floodplains that flow into to smaller surface features that run through the urban lot fabric.

Engineered floodplain limits are determined through
extensive engineering analysis of the valley system.  More
local overland flow limits may be determined through a
local flood remediation study that analyzes the 'major system'
of road drainage as if it is a river valley. That can be
 expensive. Alternatively the risk of being close to the
overland flow path can be estimated by defining buffer
distances from small and large runoff area flow paths.
The key overland flood risk factor is whether the property is on the overland flow path where the drainage accumulates. Maybe a property is at a sag in a road where runoff could spill toward the property (i.e., it's vulnerable to overland flooding) but if there is no large upstream area contributing overland runoff toward the property, its not exposed to meaningful risk. But with a large overland drainage area from the neighbourhood flowing into the sag there is a risk to the property.  And in that case, disconnected downspouts won't help reduce risk - downspouts drain a couple hundred square meters of rooftop, while large overland catchments can be a couple hundred hectares (meaning 10,000 times greater than the local roof area)
GIS Tools can identify major sags, or depressions,
 (called sinks) in the landscape that can indicate or amplify
overland flood risk.


Neighbourhood scale risks factors for overland flooding can be assessed with some minor effort (relative to detailed pipe-by-pipe sewer and street-by-street hydraulic simulation models that is) by just considering topography from readily available elevations models and by applying core GIS hydrology tools.

The image to the left on 'major sags' is an example showing overland flooding risks including dwellings within poorly-drained sags.  In this case it includes dwellings upstream of a railway embankment that can impede and 'back up' flows during large events.

Ranked property risk considering proximity to overland flow
path, drainage area, and major sags in topography
 (i.e., drainage-challenged during extreme runoff events).
The risk to dwellings and property within close proximity to overland flow paths can be ranked. For example a building within 3 m of a 10 hectare area runoff flow path, or 15 m from 100 hectare area flow path, would be at relatively low risk. Alternatively a dwellings within  3 m of a 100 ha flow path would be at a high risk.  A building within both a flow path and in a sag would be at the highest risk. Remember, these are estimates and are qualitative.  Nonetheless, experience shows that areas identified through these heuristic methods have be subject to overland flooding during extreme rainfall events.

The issue with overland flood insurance (urban, table-land type flooding) is that risks are concentrated with a small portion of downstream properties for whom risk-based premiums could be unaffordable, or for whom coverage would not be available.  The majority of upstream properties would not likely ever experience overland flooding nor add coverage for it. So overland flood damages are not like wind damage (path of wind can be anywhere whereas path of water is always the lowest elevations).

At a property scale, a property with poor lot grading and a reverse slope driveway may be at high risk regardless of proximity to overland flow paths or major sags in topography. Such a property would benefit from having an overland flood endorsement in its water protection insurance. Ideally homeowners in this situation can take action to mitigate risks by improving grading, installing barriers to flow from the reverse drive, keeping grates clear of debris and perhaps installing a backflow valve on the driveway drain.  Beyond these exceptions, anyone with foundation drains that could clog or a service lateral that could become root infested is at risk of flooding - but that would not be overland flooding, but rather back-up from the floor drain or seepage from the foundation wall and cracks (a different endorsement all together).

Check out new analysis of table land flood risks and insight into correlations with basement flooding / sewer back-up incidents : overland flow flood risk factors