Protecting Heritage Resources from Flooding – the US Experience

In an earlier article “Is Enough Being Done to Protect European Cultural Heritage Resources From Flood Risk?” FloodList examined the process of incorporating disaster protection for heritage resources into broader disaster risk reduction programmes in the European region.

This article will look at the US experience in protecting heritage resources from flooding.

Background

In the 2007 European Parliament study ‘Protecting the Cultural Heritage from Natural Disaster’, it is stated that, “(u)nlike Europe, where there is still no central coordination of emergency situations, in the United States the Federal Emergency Management Agency (FEMA) was founded in 1979…(which) integrated all the formerly dispersed structures of activities in the field of so-called disaster mitigation.”

FEMA

In 2005, FEMA published an informative ‘State and Local Mitigation Planning How-to Guide’ titled “Integrating Historic Property and Cultural Resource Considerations into Hazard Mitigation Planning (pdf)”. This useful document provides broad-brush guidance for ensuring that heritage resources are not neglected during the disaster management planning process.

National Parks Service (Department of the Interior)

Where historic buildings suffer damage due to natural or man-made disasters, the National Parks Service, through its Heritage Documentation Program, is custodian to a permanent collection of “architectural, engineering and landscape documentation at the Library of Congress consisting of measured and interpretive drawings, large-format black and white and color photographs, written historical and descriptive data, and original field notes”, that can be used to restore them. In addition, the NPS provides standards and guidelines for architects, engineers, QA’s and other professionals on how to compile records of historical buildings for future reference for restoration work.

Shortfall in Implementation

Nevertheless, in an April 2016 article “Disaster plans often neglect historic preservation”, research by the University of Colorado, Denver indicated that “many communities fail to take historic preservation into account when planning for natural disasters, risking a loss of heritage and critical engines of the local economy in the event of catastrophe.”

The study, entitled “Building Community Resilience Through Historic Preservation”, is supported by a review of historic preservation and hazard mitigation plans in all 50 states in the USA, and identified numerous historic sites located in hazardous areas such as the 100-year floodplain. One of the catalysts of the study was the loss of several historic buildings during catastrophic floods in Colorado in 2013.

The study, authored by Andrew Rumbach, assistant professor of planning and design at CU Denver’s College of Architecture and Planning, and co-authored by Douglas Appler, the Helen Edwards Abell Chair in Historic Preservation at the University of Kentucky, was published in the Spring 2016 edition of the Journal of the American Planning Association (JAPA).

Whilst Rumbach found exemplary historical resource protection plans in some states such as North Dakota and Florida, the study found that 60 percent of state hazard mitigation plans did not include a representative of historic preservation on the core planning team.

“Many disaster mitigation plans make no mention of historic resources,” he said, adding “As more and more communities bank on historic resources to benefit the local economy, this needs to be remedied.”

The research, he hoped, would “help bring about an improved understanding of what must be accomplished to protect and benefit from historic resources during the disaster planning and recovery process.”

The historic city of Ellicott, Maryland, after the devastating floods of 2016. Photo: Forsaken Fotos, CC BY 2.0

Keeping History Above Water

One example of a local community attempting to implement this combination, in the face of the threat of climate change and sea level rise, is found in the city of Newport, Rhode Island. Indications are that the mean high tide at Newport has risen 11 inches (27.9cm) in the last 100 years, and historical data suggests that the rate of sea level rise is increasing.

Washington Street House, Newport, Rhode Island. Photo: Daniel Case, CC BY-SA 3.0

The Newport Historic District was declared a National Historic Landmark District in 1968, but increased flood activity and sea level rise predictions are a growing threat to the district. In April 2016, the Newport Restoration Foundation (NRF) hosted the first Keeping History Above Water (KHAW) conference, and used a property in the Point Neighborhood of the town, the Christopher Townsend House at 74 Bridge Street, as a case study.

According to the study, there are 968 historical structures (of which 74 Bridge Street is one) located in the Newport floodplain, with an assessed value of US$559,992,649. Total potential property loss within the floodplain area is estimated at US$3.8bn.

Case Study

The earliest part of the house at 74 Bridge Street has been dated back to about 1728, when the property was owned by the father of the renowned cabinet maker John Townsend, and it has survived many floods. At present, however, sea level rise has brought the groundwater level up to above the basement floor level, and two sump pumps are in constant operation. All electrical wiring and appliances have been raised to the level of first floor framing or higher. Nevertheless, it is estimated that, by 2050, the Mean Highest High Water level (MHHW) could have increased by a further 21 inches (53.3cm).

In order to comply with the current FEMA elevation requirement, the floor level of the house would need to be raised some 7 feet (2.13m), with associated implications for its aesthetics and heritage characteristics, and the street frontage as a whole.

Investigating alternatives, the case study proposes short term remedies which include filling in the basement to a level of 3 feet (90cm) above its present floor level, leaving a ventilated crawl space below the first floor structural elements, and grading the site away from the building (as well as elevating the kitchen annex which is lower than the main building), but this will only protect it against sea level rise for a few decades, and not against storm surges or events such as a 100-year storm event.

Further flood protection measures would rely on the City upgrading its stormwater pipe-work and tide gates, creating neighbourhood dry-wells and cisterns, and developing its ‘green infrastructure’, such as greenways, levees and detention ponds.

A longer term vision involves elevating whole neighbourhoods at a time, with roads, infrastructure and terrain being raised along with houses, to a new safe level, or installing a large-scale flood barrier. This would obviously be extremely costly and financial mechanisms for collecting the necessary resources would be complex.

The study notes, however, that elevating all homes in the floodplain as identified by FEMA to comply with existing regulations (some 13 feet / 3.9m above NAVD88 level) would destroy the character of the Point Neighborhood, while failure to elevate the homes will make insurance and mortgages difficult or impossible to secure.

So while the solution seems to be a Catch-22 situation, the NRF is still exploring options and partnerships, whilst offering its experience for others to learn from. A further multi-disciplinary, national-reach KHAW conference is planned in conjunction with US/ICOMOS for November 2017.