Earth's Water Systems

An Exploration of Power Dynamics Across Scales

An image of the Snake River in Idaho, surrounded by green golf courses and otherwise brown and red basalt cliffs and dry scrub grasses

Introduction

Each of the systems briefly mentioned in the agenda setting paper "Setting a Pluralist Agenda for Water Governance: Why Power and Scale Matter" can be explored more in depth through this interactive Story Map. Clicking the green "Find Out More" button in each slide of the global tour below will skip directly to that section of the story map. Each section features a map that illustrates some of the geography in a given system and features an excerpt from circulated documentation that each co-author provided to each other to provoke discussion. The authors sincerely appreciate your interest!

The Trinity Aquifer

The Trinity Aquifer. Click to expand.

An important system that stands to provide a large percentage of drinking water to highly populated and growing areas of Texas. Aquifer governance in the state can be a stumbling block for long term viability of the system, however.

The Nile River Basin

The Nile River Basin. Click to expand.

The Nile is one of the most iconic river systems in the world, as well as the longest. It serves as a primary water source for Egypt, Sudan and Ethiopia, but its management has been fraught for decades due to unilateral decisions made by the British Empire before decolonization.

The Colorado River Basin

The Colorado River Basin. Click to expand.

The Colorado River provides water to many of the American Southwest population centers. The river water is overallocated and many years of harsh drought have called into question the management practices of the past and how to ensure the viability of the system as we move into a more climatically extreme future.

The Lower Rio Grande System

The Lower Rio Grande System . Click to expand.

The Rio Grande System, south of Elephant Butte Reservoir is heavily anthropogenically modified for the agriculture industry, but climate change induced reductions in snow melt to feed the river is impacting its ability to sustain irrigation. This is extremely difficult for individual farmers who may be dependent on their produce to survive, and raises many questions about the management of transboundary water systems and how to best ensure the equitable distribution of water.

The Whanganui River Basin

The Whanganui River Basin. Click to expand.

The Whanganui River is an integral water source for many industries and people in New Zealand, and like many systems, has seen variable management strategies for its long term sustainability. Whanganui has recently become one of the first river systems to be granted legal personhood through the efforts of the various Maori Iwi (Tribes) who consider it, and its connected systems as an honored ancestor. It represents a potential new paradigm where indigenous peoples are chief participants in the management of water systems that their ancestors sustainibly used for generations.

The Columbia River Basin

The Columbia River Basin. Click to expand.

The Columbia River Basin of the Pacific Northwest Region in the United States is a large basin that has seen increasing tensions arising from the past installation of dams for hydropower generation causing damage to vulnerable species like salmon and affecting environmental flow regimes in the river. Additionally, as drought becomes more frequent and severe in the region, evaluating the long term costs and benefits of those hydropower systems becomes more difficult and critical.

The Saskatchewan River Basin

The Saskatchewan River Basin. Click to expand.

One of the larger river basins in Canada, the Saskatchewan basin has seen numerous anthropogenic changes to its river and wetland systems. Dams and constructed reservoirs have reduced seasonal flooding to the culturally significant delta wetlands, while agricultural pollution has caused continuingly worsening issues along the river reach.

The Koshi River Basin

The Koshi River Basin. Click to expand.

The Koshi River basin is an important tributary basin to the Ganges River in the Himalaya Region. The Roshi Watershed, a sub basin of the Koshi, and the town of Dhulikhel, have recently seen political turmoil as the heavily urbanized city of Kathmandu to the west has begun to exert more control on the water in the Roshi watershed despite being hydrologically disconnected from the basin aside from pipelines.

O'ahu, Hawai'i

O'ahu, Hawai'i . Click to expand.

The challenges of island water systems, like those on the Hawaiian Islands, are as multi faceted and complex as any across larger spatial extents, but with the added caveat of there being less water volumetrically than might be available in other systems. Therefore, when crises occur, such as the Red Hill Fuel Storage Site spill, in O'ahu, it is critical that actors and stakeholders act in concert to reduce the impact of such events.

The Coastal Aquifer System

The Coastal Aquifer System . Click to expand.

The vulnerabilities of coastal aquifer systems along the Eastern Coast of the United States are exemplified by the aquifer used by the city of Dover, Delaware. There are tensions between the municipality's use of the groundwater causing salt water intrusion to affect the farmers outside of the city who also use the groundwater for irrigation.

The Trinity Aquifer

An important system that stands to provide a large percentage of drinking water to highly populated and growing areas of Texas. Aquifer governance in the state can be a stumbling block for long term viability of the system, however.

The Nile River Basin

The Nile is one of the most iconic river systems in the world, as well as the longest. It serves as a primary water source for Egypt, Sudan and Ethiopia, but its management has been fraught for decades due to unilateral decisions made by the British Empire before decolonization.

The Colorado River Basin

The Colorado River provides water to many of the American Southwest population centers. The river water is overallocated and many years of harsh drought have called into question the management practices of the past and how to ensure the viability of the system as we move into a more climatically extreme future.

The Lower Rio Grande System

The Rio Grande System, south of Elephant Butte Reservoir is heavily anthropogenically modified for the agriculture industry, but climate change induced reductions in snow melt to feed the river is impacting its ability to sustain irrigation. This is extremely difficult for individual farmers who may be dependent on their produce to survive, and raises many questions about the management of transboundary water systems and how to best ensure the equitable distribution of water.

The Whanganui River Basin

The Whanganui River is an integral water source for many industries and people in New Zealand, and like many systems, has seen variable management strategies for its long term sustainability. Whanganui has recently become one of the first river systems to be granted legal personhood through the efforts of the various Maori Iwi (Tribes) who consider it, and its connected systems as an honored ancestor. It represents a potential new paradigm where indigenous peoples are chief participants in the management of water systems that their ancestors sustainibly used for generations.

The Columbia River Basin

The Columbia River Basin of the Pacific Northwest Region in the United States is a large basin that has seen increasing tensions arising from the past installation of dams for hydropower generation causing damage to vulnerable species like salmon and affecting environmental flow regimes in the river. Additionally, as drought becomes more frequent and severe in the region, evaluating the long term costs and benefits of those hydropower systems becomes more difficult and critical.

The Saskatchewan River Basin

One of the larger river basins in Canada, the Saskatchewan basin has seen numerous anthropogenic changes to its river and wetland systems. Dams and constructed reservoirs have reduced seasonal flooding to the culturally significant delta wetlands, while agricultural pollution has caused continuingly worsening issues along the river reach.

The Koshi River Basin

The Koshi River basin is an important tributary basin to the Ganges River in the Himalaya Region. The Roshi Watershed, a sub basin of the Koshi, and the town of Dhulikhel, have recently seen political turmoil as the heavily urbanized city of Kathmandu to the west has begun to exert more control on the water in the Roshi watershed despite being hydrologically disconnected from the basin aside from pipelines.

O'ahu, Hawai'i

The challenges of island water systems, like those on the Hawaiian Islands, are as multi faceted and complex as any across larger spatial extents, but with the added caveat of there being less water volumetrically than might be available in other systems. Therefore, when crises occur, such as the Red Hill Fuel Storage Site spill, in O'ahu, it is critical that actors and stakeholders act in concert to reduce the impact of such events.

The Coastal Aquifer System

The vulnerabilities of coastal aquifer systems along the Eastern Coast of the United States are exemplified by the aquifer used by the city of Dover, Delaware. There are tensions between the municipality's use of the groundwater causing salt water intrusion to affect the farmers outside of the city who also use the groundwater for irrigation.

Trinity Aquifer System

Trinity Aquifer

Map Description

The map above depicts the full geographic extent of the Trinity Aquifer. The solid red in the western half of the aquifer depicts the outcropping portion and recharge area of the aquifer. The cross-hatched section to the East shows the down dip portion of the aquifer. The geologic formations that form the Trinity continue to dip downward along the same trend, but rather than extend the aquifer boundaries to their geological maximum extent, the eastern border of the aquifer is instead, the bad water line, where wells drilled into the same formation produce water that contains too many dissolved solids to be considered useful.


Document Excerpt

"The Trinity Aquifer is a large aquifer system whose geologic history means that it can be difficult to evaluate the health of the whole aquifer using one set of criteria. This, combined with Texas’ relatively weak groundwater regulations means that mismanagement can easily occur in a system that provides water for a huge swath of the state. There are a few key points where the mismatches in power dynamics and scale play out. First, is the mismatch between the use of the aquifer, the management plan of the aquifer as a whole (written by the Texas Water Development Board, a state level agency), and the actual reality of the aquifer dynamics. The layers of the Trinity that provide most of the water are deep confined formations that take thousands to tens of thousands of years to recharge, this is in contrast to the management plan for the state of Texas which is updated every 5 years and the use of water on the daily all across the aquifer. Because aquifer dynamics are so slow and generally visually inaccessible, its very common for use to outstrip recharge and thus drain the aquifer over time changing its dynamics seasonally and potentially affecting the potential return to a less disturbed state. There is also a mismatch in terms of the power of individuals to be somewhat unencumbered by the rules and regulations that larger entities must follow with regards to groundwater use. The state has set an arbitrary limit on daily pumping from individual wells but does not allow for conservation districts to monitor those same wells and ensure that that limit is being followed which is a departure from traditional power relationships that typically allow an overseeing body to exert some sort of authority over those that are smaller than themselves. In addition... counties in the state do not have conservation districts to do any kind of aquifer health/monitoring/ assessment meaning that groundwater in those areas is entirely governed by the rule of capture and ultimately could affect those counties with districts that border them negatively as the water is used across the aquifer. The disconnects in the Trinity, I would hazard, are frequently due to a lack of understanding that a single groundwater user literally affects everyone else in the system but due to the spatial scale and spread that these effects occur over, they are quite small on a per person basis. " - Will Brewer

The Nile River Basin

The Nile River Basin

Map Description

The map above depicts the full extent of the Nile River Basin in Eastern Africa. The blue line represents the Nile. The city of Khartoum, Sudan sits on the confluence between the Blue Nile and the White Nile. The river flows generally South to North. Also visible on the map are Lakes Kivu, Albert and Victoria, each an important water source for surrounding areas. Zooming in north of the Aswan Lake in southern Egypt, aerial imagery of the Aswan High Dam becomes visible.

Document Excerpt

"The Nile is a large and complex river basin. There are myriad power issues at play, but one of the most salient is the tensions between the lower (Blue Nile) basin riparians. The push and pull of power is fascinating because Egypt – the downstream state – has historically been the regional hegemon and has held water rights allocated during the British colonial period via treaty. To that end, as other riparian states have developed and increased in political clout, they contested Egyptian claims over the majority of water. Ethiopia has, since the Arab Spring, been emerging as the new regional hegemon and the most vocal opposition to Egypt’s water usage (note: the Ethiopian civil war has complicated this). In lieu of formal treaty power, and in a moment of Egyptian domestic unrest, Ethiopia has de facto usurped power over the water (practical power) by building the Grand Ethiopian Renaissance Dam. This international power display belies power issues at the domestic level between agricultural and municipal users (as cities grow and countries urbanize), and more." - Rosa Cuppari 


The Colorado River Basin

The Colorado River Basin

Map Description

This map depicts the full extent of the Colorado River Basin in the Southwestern United States. The upper and lower basin are outlined in two separate shades of blue along with the Colorado River itself and some of its major tributaries. Large water bodies (In this case, bodies of water with greater than 3 square kilometers of surface area) are also shown as dark blue shapes. Black dots along the river lines are dams. Upon zooming in, the land use and land cover classifications for the basin becomes visible. Red shades are urbanized areas, greens are typically forested, and the tans and golds represent desert scrub, rangeland and cultivated crops.

Document Excerpt

"The Colorado River sprawls across the southwestern United States draining more than 600,000 square kilometers and providing water to approximately 40 million people and irrigating over 5 million acres of farmland. The vast majority of water in the Colorado River (85-90%) originates as snowpack in the Rocky Mountains in Colorado, Utah, and Wyoming and historically the hydrologic cycles in the river peaked in spring during snowmelt and dwindled to baseflow during the fall and winter months. Extreme hydrologic variability in the river has led to the construction of over 100 dams and impoundments; at least 46 of these are classified as large dams (> 76 m structure or > 62 million m3 of storage capacity). The two largest  reservoirs on the river are Lake Mead and Lake Powell, which have a combined storage capacity of 63.3 km3, equivalent to over 4 years of average (1990-2020) annual river discharge. Currently, both reservoirs hold less than 25% of full capacity. 

The Colorado River runs some 2,300 km through 7 U.S. states, two countries, and at least 27 federally recognized tribes before reaching its sink—either flowing to its delta in the Gulf of California or disappearing into the sands of the Sonoran Desert. 

Water use in the Colorado River is dominated by the $8 billion dollar agricultural sector which it supports; agricultural uses account for 70-80% of consumptive uses and losses in the river. The Yuma, Imperial, and Coachella valleys rely heavily on Colorado River water for irrigation and are responsible for 90% of winter greens consumed in the United States and 80% of global almond production. Agriculture has been the majority water use group in the Colorado River since the late 19th century. However, rapid growth of urban areas has increased municipal water demands across the region. Municipal water rights include both “basin cities,” which lie within the geographic boundary of the Colorado River and have water rights with both diversion and return flows, and “trans-basin cities,” which have diversion water rights but no obligation of a return flow (100% consumptive use rights). " - Tanya Petach


The Lower Rio Grande System

The Lower Rio Grande

Map Description

This map depicts the extent of the area known as the Lower Rio Grande. Shown are the basin outline, the Rio Grande River and its major tributaries and some of the prominent reservoirs along the river reach in the basin, including Elephant Butte Reservoir, near Truth or Consequences, New Mexico. Also shown is the land use/land cover for the basin, where red shades represent urbanized areas, green represent forested areas, and tans and golds represent desert scrub and cultivated crops or grasslands.

Document Excerpt

"At the beginning of the 20th century, physical infrastructure (like dams, canals, and ditches) and social infrastructure (like laws, water user associations, bureaucracies, and institutions of water management) were created to support the most important regime of capital accumulation of the time—irrigated agriculture—along the border (Walsh 2013, 2). Currently, however, the most important regime of capital accumulation along the border is urbanization, industry, and service economy (Walsh 2013:2). These physical and legal infrastructures reflect the power relationships at the time of their creation and are difficult to change in light of new social structures, priorities, and environmental shifts. For example, some environmental organizations have proposed that water not be held at Elephant Butte at all, citing its lower elevation and higher temperatures when compared to areas in the Rio Grande watershed in Northern New Mexico. However, legal arrangements that measure deliveries in and out of Elephant Butte are difficult to change. The irrigation infrastructure and the recreation infrastructure that have developed over the last century of the Elephant Butte Reservoirs existence are also difficult to change.

Additionally, the farmers in the Elephant Butte Irrigation District are senior water rights holders in the LRG, yet those rights are being challenged by Texas in a lawsuit against New Mexico for pumping groundwater that affects Texas’ surface water (Rio Grande) deliveries. The case is currently in the US Supreme Court. Just this January details of a consent decree (an agreement by TX, NM, and CO) was released to the public. The states involved are in agreement to the new terms, but the federal government remains opposed to the settlement. In this case, there is conflict across scales between local water use, state to state legal delivery obligations, state’s agreements to new terms, and the power of the federal government to disregard the wishes of the states." - Holly Brause


The Whanganui River Basin

The Whanganui River Basin

Map Description

The Whanganui River Basin, of Aotearoa New Zealand, is depicted in this map. Visible, are the river and its catchment area, as well as the two National Parks that intersect the catchment basin. The primarily green layer is land cover in the catchment, depicting the various forest types in green as well some urban development in grey and cultivated areas in tan and gold.

Document Excerpt

"This case is a leading example of disrupting power relations in complex water system governance - by (a) providing space within legal and management frameworks for Indigenous peoples to exercise their place-based authority over river governance, and (b) providing voice for the river and its interests to be a central consideration in decision making that affects it. Still, scale mismatches complicate processes of power-shifting. Examples of this, in terms of spatial scale, are that decision making about river use are typically made by regional authorities that operate at a larger scale than the catchment, are disconnected from local circumstances, and are influenced by national policy considerations and directives. The Whanganui Iwi (Indigenous peoples of the river) have spent much time, effort and money, engaging with national and regional authorities and stakeholders to try and get them to engage with the river at a local river scale (including respect for local river authority and culture). In terms of temporal scale, Iwi river management operates on multi-general timeframes, as Iwi manage resources handed down by ancestors and in the interests of future generations. This is a challenge for national and regional authorities and stakeholders (and their laws and practices) who operate on short-term political and economic cycles - for example a 4 year electoral term. " - Elizabeth Macpherson


The Columbia River Basin

Columbia River Basin

Map Description

The Columbia River Basin is depicted above. The two major rivers in the basin, the Columbia and Snake are shown as blue lines (with the lighter blue being the Columbia). Additional to the major rivers, the dams in the basin are shown as points of different shapes and colors depending on the ownership of the dam.

Document Excerpt

"There are several actors with varying levels of power in the Columbia, but the most notable are: indigenous groups, the regional utilities (BC Hydro in Canada and the Bonneville Power Administration in the US), federal entities (the US Bureau of Reclamation/Army Corps of Engineers*, US government, Canadian government), and states/provinces in the basin (i.e., British Columbia, Washington, Oregon, Idaho, parts of Montana/Wyoming/Nevada). The environment, in particular the river and its tributaries and the native fish species, are another broad set of actors, which have been long ignored, to the extent that many fish species have been protected under the federal Endangered Species Act. At the same time, federal legislation guides the operations and mandate of BPA, which is to provide low-cost power to regional customers, though BPA has no practical power because federal agencies control dam operations. Federal jurisdiction further relates to the Columbia River Treaty between the US and Canada; though BPA and BC Hydro are interested parties, they are beholden to final federal policy. Lastly, indigenous groups, which have long been connected to the river, have long been excluded from negotiations and marginalized." - Rosa Cuppari 


The Saskatchewan River Basin

The Saskatchewan River Basin

Map Description

The Saskatchewan Basin, primarily of Canada is depicted in the map above. Visible on the map are the various ecoregions of the basin as well as the Saskatchewan River itself and its major tributaries. Shapes in coral with black outlines are the state defined Aboriginal Land Boundaries in Canada. Additionally visible are some of the large water bodies in the basin including some wetlands and lakes. If the map is zoomed in, the land cover of the basin becomes visible, showing the large amount of agriculture throughout the center of the basin.

Document Excerpt

"At (large) basin scale, the Saskatchewan River basin is managed by the Prairie Provinces Water Board (PPWB), which consists of representatives from the three Provinces (Alberta, Saskatchewan, Manitoba), and the Federal Government (Environment and Climate Change Canada). At a provincial level, provincial government agencies are responsible for water management. Both the provincial government agencies and the PPWB are sensitive to provincial political pressures and priorities. The agricultural sector is an important component of the regional (and national) economy, and, together with mining and oil and gas, has a large political presence.

Flows between upstream and downstream Provinces are determined by a 1969 Master Agreement, developed in an era strongly focussed on economic development, and at a time when major dam construction was underway. The Master Agreement remains largely unquestioned. However an important consequence of the 1960’s dam construction has been a major change to the river’s natural flow regime, with a loss of summer flood flows, and higher winter flows. This, together with construction of a hydropower dam (the E B Campbell dam) immediately upstream of the Saskatchewan delta, has had major impacts on the internationally-significant delta wetland ecosystems, home to two First Nations communities. While the dams have reduced summer flooding, which historically isolated these communities through loss of road access for up to 6 weeks, loss of the associated wetland inundation has seriously degraded the wetland ecosystems, on which the First Nations rely for hunting, trapping, fishing and associated tourism activities. The First Nations feel disempowered. However, they are included in current discussions over re-licensing of the EB Campbell dam...

... Also at a local scale, recent flooding has focused attention on the major loss (of some 80%) of wetlands in the prairies, mainly due to agricultural practices. These wetlands naturally retained water, and nutrients. Historically little action has been taken, despite downstream communities (including First Nations) being flooded, reflecting the past political environment. However, the problems have become so severe that legislation has recently been implemented to require licensing of current and historical drainage – a very challenging task given the complex environments and long historical legacies." - Howard Wheater


The Koshi River Basin

Dhulikel Nepal

Map Description

A section of the Koshi River Basin is shown in the map above. The Koshi basin is outlined in red and the Roshi sub-basin is outlined in tan. Heavily urbanized areas are shown in yellow and the town of Dhulikhel is outlined in a shade of red. Steams and rivers are shown in blue. Note that the major city of Kathmandu does not fall within the Roshi sub basin and, is in fact, separated from the Roshi by a hydrologic divide as depicted by the stream lines.

Document Excerpt

"Roshi watershed lies on Koshi basin, the largest river basin of Nepal and is also a major tributary of Ganges.  Roshi watershed is important as it supplies water to population of 66,405 of Dhulikhel and its surrounding town which is 35 Km far from close to capital city Kathmandu and nearly the same number of floating population of tourists and students for purposes beyond ‘drinking’ as well as for the irrigation of  the small farmers communities living in the upstream region. This watershed is crucial as this provides a striking example of water-related negotiations that involve incentivizing the water-rich upstream community, explicitly by providing economic incentives, and implicitly by mobilizing socio-political position and interpersonal relations since 1985 AD through community led negotation. Dhulikhel town is not downstream geographically but considered downstream through connection through 14 km  of pipeline. Therefore in this case water is “connecting agent”, where pipelines physically connect communities  and create a complex hydro-social space spanning rural and urban areas..." - Kaustuv Neupane


Basal Aquifer System, O'ahu

Hawaii

Map Description

The map above shows an aerial view of Honolulu, Hawai'i. The shapes of various colors represent active US military sites. The blue lines represent the Hawaii Department of Health's designated aquifer systems. The purple outline is the Red Hill fuel storage site and the blue circles within represent the sampling wells used by the EPA to monitor the fuel leak plume from the Red Hill site.

Document Excerpt

"Island catchments are often characterized by a single lowland population benefiting from the conservation/protection of upland montane forested recharge zones largely managed by the state. In the Hawaiian Islands, current day water conflicts are the legacies of historical diversions of water from resident communities in wet regions to leeward dry regions supporting commercial sugar production. As the era of big agriculture wanes, communities have been reclaiming waters on the basis of environmental and public trust protections enshrined in the Hawaii State Constitution and Water Code. Many of these conflicts are occurring in rapidly-developing rural areas and islands where former agricultural lands are being converted to housing developments driven by a hot real estate market/ real estate investment supported by county agencies reliant on property taxes and susceptible to rhetoric of “job creation” and “affordable housing.” As flows return to streams, water withdrawers are increasingly looking to groundwater as a more reliable and less contentious source of water...

...The heavily urbanized island of Oʻahu (population ~1 million, area of 1500 km2), depends heavily on minimally-treated groundwater for water supplies. A recent contamination event of the southern Oahu basal aquifer in the proximity of the US Navy’s Red Hill Bulk Fuel Storage facility in late 2021 has brought the vulnerability of the island’s water supplies into sharp focus.  For years, the local state government has been relatively impotent/unwilling to enforce environmental regulation on the Navy and its 80 year old facility with capacity of 250 million gallons of fuel storage in 20 massive underground storage tanks sitting 100 feet above Oahu’s most valuable aquifer. Concerns over the risks of contamination from fuel release have been raised primarily by environmental NGOs and the local, municipal Honolulu Board of Water Supply, which relies on nearby Halawa shaft to support 20 percent of its service to metro Honolulu. In late Nov to early Dec 2021, a slug of jet fuel and water on the order of tens of thousands of gallons was released almost directly into the infiltration gallery/groundwater development tunnel supplying the Navy’s own drinking water distribution system. This resulted in acute exposure/consumption of fuel-laced water by residents and tremendous public outcry. Both the Navy and the HBWS ceased pumping at highly productive Red Hill and Halawa shafts, shifting water sources to other wells further from the immediate vicinity to avoid (continuing) pulling contaminants into their drinking water distribution systems.  Straddling two aquifer sector areas of Pearl Harbor and (overallocated) Honolulu, the shift in pumping also raises issues of the long term sustainable management of water for both municipal and multiple public trust purposes in the face of both climate change and contamination..." - Aurora Kagawa-Viviani


The Columbia Aquifer System

Columbia Aquifer System

Map Description

This map depicts the coastal Columbia Aquifer system of Delaware and surrounding areas, zoomed to the Dover area. The aquifer is depicted in blue. The numerous agricultural areas are depicted in bright green. The municipal well field that provides water for Dover is outlined in red. Zooming in, the land cover for the area is shown, with agricultural land in tans and golds and urban cover in shades of red.

Document Excerpt

"The Columbia Aquifer centered in Dover, Delaware is the location of a challenging water management example, spanning multiple spatiotemporal scales and administrative power mismatches. The surficial Columbia aquifer is important for supporting agricultural and domestic water uses and the near-shore saltwater marshes. As this aquifer is pumped (at a much faster rate than it can naturally replenish itself), the freshwater resource is at high risk of contamination from saltwater intrusion (SWI).  SWI occurs from both short and long-term processes as well as surface and subsurface events. For example, two mechanisms affecting the Columbia Aquifer, include (1) subsurface, lateral intrusion of seawater into freshwater aquifers driven by rising sea levels and groundwater pumping, and (2) surface inundation from storm surges. 

The impacts of SWI can be devastating if proper management is not achieved. Agricultural users tend to be closer to the coast, and therefore at higher risk of contamination, than large-scale municipal and industrial water users. Yet municipal pumping quantities and rates are often orders of magnitude greater than irrigation pumping, meaning municipal wells can lead to increased SWI. There is a mismatch between those affected by SWI and those causing SWI.  The multiple independent groundwater users each make a pumping decision that can potentially affect the other water users. The impacts of pumping decisions depend on the distance between users, past pumping behavior, and a time lag. In other words, pairs or groups of groundwater users can have unique and bilateral effects on each other. The Delaware Department of Natural Resources and Environmental Control Water Allocation Branch oversees major water withdrawals from both surface water and groundwater across the state. A permit is required for all major water withdrawals greater than 50,000 gallons in 24 hours. However, only a small portion of irrigation wells, have complete location, construction, and pumping rate data. The number and distribution of monitoring wells are also limited." - Chelsea Peters