The United States (U.S.) Gulf Coast is a prominent global energy hub with a set of highly integrated critical energy infrastructure that rivals, if not surpass es , any comparable set of infrastructure anywhere in the world. Past extreme weather events in the region have led to critical energy infrastructure disruptions with national and global implications. Future sea-level rise (SLR), coupled with other natural hazards, will lead to a significant increase in energy infrastructure damage exposure. This research assesses coastal energy infrastructure that is at risk from various fixed SLR outcomes and scenarios. The results indicate that natural gas processing plants that treat and process natural gas before moving it into the interstate natural gas transmission system may be particularly vulnerable to inundation than other forms of critical energy infrastructure. Under certain SLR assumptions, as much as six Bcfd (eight percent of all U.S. natural gas processing capacity) could be inundated. More extreme SLR exposure assumptions result in greater levels of energy infrastructure capacity exposure including as much as 39 percent of all U.S. refining capacity based on current operating levels. This research and its results show that while fossil fuel industries are often referenced as part of the climate change problem, these industries will likely be more than proportionally exposed to the negative impacts of various climate change outcomes relative to other industrial sectors of the U.S. economy. This has important implications for the U.S. and global energy supplies and costs, as well as for the U.S. regional economies reliant on coastal energy infrastructure and its supporting industries.
The exact amount of future sea level rise (SLR) is uncertain [
SLR can have broad impacts on energy systems affecting a number of sectors [
These very limited past experiences bode ill for the future of a large amount of Gulf Coast energy infrastructure. Considering the number of major flood events, comparable to the events like Hurricane Harvey, it is expected to increase since the annual likelihood of area-integrated precipitation in excess of 50 cm is also forecast to increase by as much as 18 percent during the 2081-2100 period. This is significantly higher than the one percent probability seen for similar events during the 1981-2000 period [
The U.S. Gulf Coast has one of the most developed, and comprehensive energy economies in the world. This extensive energy economy is supported by a vast network of highly integrated infrastructure that is located in what experts and laypersons would appreciate as being “harsh”. Extreme temperatures, high humidity, a relative low-elevation, and exposure to considerable tropical storm activity are everyday events. The region’s changing ecosystem serves as a constant threat to this critical energy infrastructure and the resources it distributes across the U.S. and the globe [
While some past academic research has recognized and explored the relationship of energy infrastructure and its environment [
The objectives of this research are to address this relationship through: (1) a review of historical SLR and regional variations across the Gulf Coast; (2) analysis of the direct impacts that SLR will likely have on specific energy system assets; and (3) examining adaptation methods, and the limitation to these methods and opportunities for future research.
Over the past several years, there has been a systematic increase in the use of SLR projections for decision making and policy planning. The use of future SLR projections is a critical first step in assessing critical energy infrastructure damage exposure. Tide gauges that provide records of historical SLR levels that span over several decades have been traditionally used to estimate future trends. Global SLR averaged 1.7 ± 0.2 mm/yr from the start of the 20th century [
Parris et al. [
The U.S. Gulf Coast is the geographical area in the southern U.S. adjoining the northern portion of the Gulf of Mexico (GoM). The coastal states that have a shoreline on the GoM are Texas, Louisiana, Mississippi, Alabama and Florida. The Gulf Coast is one of the extensively monitored regions for SLR with numerous tide gauges providing decadal-scale sea level data. These long SLR periods are valuable for assessing climate resilience of energy infrastructure investments because many of these facilities are expected to last several decades. The mean sea level trends are assessed for select U.S. stations that span the five Gulf Coast states by using the National Oceanic and Atmospheric Administration’s (NOAA) Center for Operational Oceanographic Products and Services historical tide gauge data [
Coastal Louisiana and some parts of Texas have relatively high SLR compared to other coastal states. The regions of highest SLR are recorded in the Mississippi River Delta plain, where the average rate for the period 1947-2016 is 9.65 mm/yr (Eugene Island), closely followed by Grand Isle at 9.09 mm/yr [
In Texas, the rate of SLR ranged from 1.93 mm/yr in Port Mansfield to 6.62 mm/yr in Galveston. In the eastern Gulf Coast, the lowest rates of SLR were recorded from the tide gauges along Mississippi, Alabama, and Florida coasts.
For Florida, the mean SLR rates averaged around 2.7 mm/yr during the measured period. These regional differences in SLR are significant from the standpoint of understanding coastal impacts and risk assessment because of their potentially complex interactions with other mitigating factors including sediment deposition and barrier island buffering [
that these areas will see SLR in the upper bounds of future scenarios.
One of the ancillary effects of SLR that has been well established in past research is tidal flooding [
strengthen high tide flooding impacts with increasing frequency.
The Gulf Coast is the most prominent energy producing and processing regions in the U.S., accounting for 45% of the nation’s refining capacity and 51% of its natural gas processing capacity (U.S. Energy Information Administration (EIA)). The Gulf Coast is also the largest domestic supplier of transportation fuels. Over the last six decades, this region has seen tremendous growth in physical infrastructure development to support various onshore and offshore oil and gas exploration and production (E&P) activities and is a critical component of the interconnected North American energy network.
Most of these infrastructure facilities are located near coastal areas in order to facilitate additional transportation access particularly for international commodity and product flows (
produced more than a third of the nation’s crude oil and accounted for 30% of total U.S. refining capacity.
Petroleum refineries process crude oil through a series of distillation facilities separating crude oil into its component parts to generate refined products such as gasoline, diesel, jet fuel, and heating oil, to name a few. These facilities were originally developed at the turn of the twentieth century and continue to operate, by expanding their effective capacities through a series of expansions, upgrades, and efficiency improvements often referred to as “capacity creep.” The region’s refineries were first developed to process crude oil produced within the region and, starting in the 1970s, to increasingly process crude oils from foreign sources such as Saudi Arabia, Canada, Mexico, and Venezuela. Most of the largest refineries are located along the Texas and Louisiana coasts with a number of smaller facilities located in Mississippi and Alabama.
The U.S. EIA reports that 2017 total crude distillation capacity of all refineries in the U.S. is 19 million barrels per day (MMbpd) [
The successful operation of a refinery depends on the timely supply of feedstock, electricity, and workforce availability. Any disruption in this chain greatly affects the operational dynamics of refineries. The 2004 and 2005, and later 2017 tropical seasons had considerable impacts on most Gulf Coast refineries either through facility-specific damage or through feedstock interruptions, power outages, and/or refined product transportation interruptions.
Natural gas processing plants are midstream facilities that serve as an important link between the wellhead and the burner tip. These facilities “clean” natural gas to remove moisture and impurities as well as, most importantly, the heavier hydrocarbons that are in the production gas stream. These heavier hydrocarbons include ethane, propane, butane and other commodities often referred to collectively as natural gas liquids (NGLs). These NGLs have high commercial value as energy and chemical-industry feedstock.
Most of the original facilities in the region were developed to process conventional natural gas produced along the onshore areas of the region or, increasingly from the offshore and deepwater regions of the Gulf of Mexico. While GOM natural gas production is down relative to its historical trends, these facilities are still important components of the overall natural gas value chain. The EIA reports that in 2014 there were 554 active natural gas processing plants in the U.S. with a total daily processing capacity of more than 76 billion cubic feet (Bcf) [
An electric power system is a unified, physically-connected and operated group of facilities that are involved in the generation, transmission, and distribution of power. Apart from its use for residential and commercial purposes, electricity is an essential input for the industrial operations along the Gulf Coast. Electric power generators are typically categorized by the fuel source they use and subcategorized by their specific operating technology or “prime mover”. Although power generation along the Gulf Coast includes different sources, including fossil fuels, nuclear and renewables, natural gas is the primary fuel source.
There are 3645 electric utilities with 7494 plants in the United States with 456 utilities and 731 operable plants located in the study region of Texas, Louisiana, Mississippi, Alabama and Florida [
Extreme weather in the past has caused substantial electricity outages, as power plants and transmission infrastructure were affected by high winds and significant flooding. At its peak, Hurricane Harvey (2017) affected more than 10,000 megawatts (MW) of electricity generating capacity in Texas. Similarly, 17 power generating facilities in Louisiana with a combined capacity of 5000 MW were shut down because of physical damage or flooding from Hurricane Katrina.
The study area consists of 139 coastal counties along the GoM as defined by the NOAA Strategic Environmental Assessments Division (
of 17,141 mi, with Louisiana contributing 7721 of these miles from its barrier islands, extensive wetlands, and the Mississippi River Delta.
The model used for estimating future SLR inundation depth and at-risk energy infrastructure facilities is adapted from the one developed by the NOAA Office for Coastal Management (
The SLR inundation extent data for the different SLR scenarios is obtained from the Office for Coastal Management Digital Coast website [
The estimation of future inundation based on predicted SLR and elevation involves many unknowns, including wetland restoration, barrier island dynamics, local elevation changes and subsidence, which make the inundation areas depicted in the SLR shapefiles and raster datasets not very precise. Hence, it is vital to focus on both the extent of inundation and the confidence levels associated with these inundation layers at different SLR scenarios. Hence, confidence level maps of these inundation layers are also downloaded from [
The critical energy sub-sectors selected are petroleum refineries, natural gas processing plants, and power generation plants as overviewed earlier. These infrastructure types are selected because of the high concentration and reliance on those energy types, and their role in the energy supply chain. Historically, these were most affected facilities in the region during and in the aftermath of severe weather and hurricanes.
The possibility of structural risk to these facilities was examined because of inundation with a particular emphasis on the refining, processing and power generation capacity that may be impacted because of potential perturbations to the energy systems. Geospatial data with detailed facility-level data for each
infrastructure type are obtained from the EIA [
The 2017 EIA-820 refinery capacity report provided detailed facility-level data. Similarly, for natural gas processing plants, EIA-757 data based on a triennial survey is used for assessing the effect of extreme weather on natural gas processing infrastructure. The last updated data from this survey is for the year 2014. Power plant data is obtained from the EIA-860 Annual Electric Generator report for the year 2015. Each infrastructure type is intersected with inundation extents for future SLR scenarios of 0.61 m (2 ft), 1.22 m (4 ft) and 1.83 m (6 ft), and the locations of existing refinery, natural gas processing and electric generator facilities that are in the inundation zones are identified.
For facilities that are not directly in the inundation zone, a proximity analysis is carried out to determine the likelihood of a facility being impacted by SLR and resulting flooding and storm surges from receding shorelines. In essence, structure proximity to the future shoreline is used as a proxy for storm surge and flood impacts. Based on the proximity of these facilities, ones that are within 1 km, 2 km and 5 km from the inundation zones are identified. National Oceanic and Atmospheric Administration identifies that some Gulf Coast areas are extremely vulnerable to storm surges because of a flat continental shelf and low-lying areas extending well inland. Because of the complex interaction between storm surges, flooding and local geophysical characteristics, there no single set of variables that can be applied to all instances for these proximal facilities [
The inundation analysis shows that an additional 19,496 km2 of coastal Gulf is at risk because of inundation under a 0.61 m (2 ft) SLR scenario compared to the base scenario where there is no risk from SLR. This corresponds to a 29% increase of land area that will be under the coastal inundation zone compared to a no SLR scenario. This inundation area grows by a further 6568 km2 at 1.22 m (4 ft) SLR (7.5% increase) and by 6111 km2 at 1.83 m (6 ft) SLR scenario (6.5% increase).
An illustrative example of the inundation extent in the Mississippi River Delta plain for different SLR scenarios against the location of energy facilities is shown in
The Chevron Refinery located in Pascagoula (Mississippi), with a capacity of 370,000 barrels per day (bpd), is the only facility that is directly located in the inundation zone at 1.83 m (6 ft) SLR, and there are no facilities located in the extended area of inundation at the 0.61 m (2 ft) and 1.22 m (4 ft) SLR scenarios. However, the potential risk of inundation and flooding because of the proximity of these facilities at increased inundation level at 2 ft, 1.22 m (4 ft) and 1.83 m (6 ft) SLR scenarios shows a much higher impact to the refineries (
There are a total of 15 facilities located in the inundation extents from future SLR scenarios (
SLRa | Facility | Operator | Capacity (MMcfd) | Confidencelb | ||
---|---|---|---|---|---|---|
1.83 m (6 ft) | 1.22 m (4 ft) | 0.61 m (2 ft) | ||||
1 | 0 | 0 | Plaquemine Plant | EnLink LIG Liquids, LLC | 225 | High |
1 | 0 | Gibson Plant | EnLink LIG Liquids, LLC | 110 | High, High | |
Lowry Gas Plant | Targa Resources | 220 | High, High | |||
North Terrebonne Plant | Enterprise Gas Processing LLC | 1100 | High, High | |||
PSI Kaplan Plant | PSI Midstream Partners, LP | 300 | High, High | |||
Williams Mobile Bay Processing Plant | Williams Mobile Bay Producer Services, LLC | 700 | High, Low | |||
1 | Barracuda Gas Plant | Targa Resources | 200 | High, High, High | ||
Burns Point Plant | Enterprise Gas Processing, LLC | 160 | High, High, High | |||
Cameron Meadows Gas Plant | PSI Midstream Partners, LP | 125 | High, High, Low | |||
Gillis Gas Plant | Targa Field Services LLC | 180 | High, High, High | |||
Grand Cheniere Plant | Plains Gas Solutions | 120 | High, High, High | |||
Larose Processing Plant | Williams Field Services Group LLC | 600 | High, High, High | |||
Neptune Gas Plant | Enterprise Gas Processing LLC | 650 | High, High, High | |||
Stingray Gas Plant | Targa Resources | 300 | High, High, Low | |||
Toca Gas Plant | Enterprise Gas Processing, LLC | 1100 | High, High, High | |||
Total | 6090 |
a. A “1” under an SLR scenario indicates that the facility is affected at that level; “0” indicates that the facility is located outside the inundation zone for that scenario. b. Inundation confidence level for the SLR scenario(s) with value “1” from left to right.
from all three scenarios, while five facilities are located in 1.83 m (6 ft) and 1.22 m (4 ft) scenarios, and not in the 0.61 m (2 ft) scenario. Compared to refineries and power generating plants, more NGP facilities are located in the direct zone of inundation even at lower SLR scenarios.
In total, there are 16 power generators that are located in the inundation extents from future SLR scenarios (
Because of the economic dependence of coastal communities on the energy industry in the region, Gulf Coast will benefit from adaptive practices to improve resilience to natural hazards associated with SLR. Hurricane storm surges and coastal flooding will continue to pose growing problems to critical infrastructure more than ever before. As part of these adaptive measures, some local and regional governments are already becoming more coordinated in planning and upgrading at-risk infrastructure as a means to combat SLR.
As energy infrastructure typically has long operating lifetimes, risk prevention, adaptation strategies, and protective measures are required to reduce potential adverse effects [
them vulnerable to impacts of SLR and a study of historical events that have compromised this infrastructure are important for understanding the means for adaptation [
Further analysis and additional information are needed to determine the extent to which exposed facilities would be damaged or debilitated and to project changes in energy infrastructure that could occur in the coming decades, including possible investments in infrastructure hardening and other resilience measures. Furthermore, energy system modeling is needed to understand the extent to which damaged facilities could disrupt energy services and for how long. Future research may also focus on understanding the implications of these findings for energy system reliability and resilience.
SLRa | Generator ID | Utility ID | Plant Name | Capacity (MW) | Confidenceb | ||
---|---|---|---|---|---|---|---|
1.83 m (6 ft) | 1.22 m (4 ft) | 0.61 m (2 ft) | |||||
1 | 0 | 0 | 148 | 12686 | Chevron Oil | 16.6 | Low |
149 | 12686 | Chevron Oil | 16.6 | Low | |||
150 | 12686 | Chevron Oil | 18.0 | Low | |||
151 | 12686 | Chevron Oil | 18.0 | Low | |||
152 | 12686 | Chevron Oil | 101.3 | Low | |||
835 | 57389 | IKEA Tampa 042 | 1.0 | High | |||
845 | 58749 | Rentech Nitrogen Pasadena Cogeneration | 15.4 | High | |||
1 | 0 | 590 | 18483 | Howard F Curren Advanced Wastewater Plant | 0.5 | High, High | |
591 | 18483 | Howard F Curren Advanced Wastewater Plant | 0.5 | High, High | |||
592 | 18483 | Howard F Curren Advanced Wastewater Plant | 0.5 | High, High | |||
593 | 18483 | Howard F Curren Advanced Wastewater Plant | 0.5 | High, High | |||
594 | 18483 | Howard F Curren Advanced Wastewater Plant | 0.5 | High, High | |||
778 | 29925 | Neptune Gas Processing Plant | 4.5 | High, High | |||
1 | 118 | 3265 | Teche | 23.0 | High, High, High | ||
119 | 3265 | Teche | 348.5 | High, High, High | |||
120 | 3265 | Teche | 42.2 | High, High, High | |||
Grand Total | 607.6 |
a. A “1” under an SLR scenario indicates that the facility is affected at that level; “0” indicates that the facility is located outside the inundation zone for that scenario. b. Inundation confidence level for the SLR scenario(s) with value “1” from left to right.
This study is not a comprehensive risk assessment of all energy infrastructures in the region, but only provides a preliminary estimation of existing critical facilities that would be exposed to greater risk as a result of SLR and secondary storm surge or flooding. Important factors not taken into account include the probability of local hurricane strikes at any given location, the depth of inundation, and the degree of damage that would occur to each exposed facility from flooding or storm-related wind damage. This analysis also does not account for methods in which SLR risk could be mitigated, such as the construction of physical barriers, including storm levees, berms, and other barriers, or raising the height of certain facilities or critical equipment located at various infrastructure locations, or other protective facilities [
Additionally, this study does not consider the likely reduction of risk because of the relocation of facilities over the next few decades that is within the timeframe of SLR projection scenarios although the likelihood of moving some of these very large facilities is quite low. Another key factor that is increasing storm surge and SLR risk is land subsidence, which, at least according to some estimates, is occurring along the Gulf Coast at rates faster than previously observed. The estimated inundation levels from future SLR scenarios assume that present geomorphological settings will continue. With continued improvement in understanding and predicting these natural processes, better estimates of SLR, and thereby better risk assessments can be made in the future.
This research assesses the potential and growing risk of SLR on critical energy infrastructure located along the Gulf Coast. Historical tide gauge station data
from decadal-scale data suggest that the areas surrounding coastal Louisiana in the Mississippi River Delta plain may have a significantly higher rate of SLR compared to other tide gauges along the Gulf Coast. This is also the area with the highest concentration of energy facilities, not only along the Gulf Coast but across the entire U.S.
Certain types of critical energy infrastructure were found in this research to be particularly vulnerable to a range of SLR scenarios including natural gas processing plants, which, given their relatively close proximity to the coast, are potentially at more risk than refineries and other forms of infrastructure that are often located in marginally more inland locations. Significantly greater numbers of facilities are present within 1000 m of the future inundation zones under different SLR scenarios indicating their susceptibility to storm surges because of their effects further inland.
This research underscores the likelihood that SLR, if left unaddressed, will likely disrupt critical energy infrastructure and the energy systems to which they are connected. These disruptions will have national and global implications. Future use of expert system-based, integrated, climate-change impact assessment models is warranted to better understand the relationships among industry and environmental variables and ensuing policy implications.
Proactive adaptation practices and improved awareness that identify potential hazards and prepare for future SLR, need to be applied more widely in vulnerable areas. Existing energy infrastructure facilities should consider conducting periodic risk assessments and assessing protective strategies to suit changing environmental conditions in order to maintain the economic value of those initial investments.
The authors would like to thank National Science Foundation (Grant No. 1212112) for their support to this project. The statements, findings, and conclusions are those of the authors and do not necessarily reflect the views of the funding agency.
Dismukes, D.E. and Narra, S. (2018) Sea-Level Rise and Coastal Inundation: A Case Study of the Gulf Coast Energy Infrastructure. Natural Resources, 9, 150-174. https://doi.org/10.4236/nr.2018.94010