Water management is one of the activities most vulnerable to the impacts of climate change. Changes in precipitation and drought, the loss of glaciers, and accelerating sea level rise directly affect the availability of water for human use, flooding hazards, and water needed to sustain natural ecosystems. But even more vulnerable are our water management institutions, including management agencies and enabling agreements such as basin compacts and transboundary treaties.
To put it simply, because of climate change, we can no longer honor many of the promises that we have made to each other.
This point was brought home to me last month. I happened to be studying a map of the Biscayne aquifer with a manager of a municipal water utility at the southern tip of Florida. The Biscayne aquifer is the sole source for freshwater in the region, and the aquifer is threatened with intrusion by seawater from three directions. So, I asked him, “When do you expect that sea level rise will force you to move your supply wells?”
“Never,” was his reply. The municipal utility is part of a regional water management district. The district limits the amount of water that the utility can get from the aquifer. In return, Florida state law requires the regional water management district to guarantee that the utility will always get the amount of water allocated to it. The purpose of the law is to regulate competition among different users vying for a limited resource.
This might have seemed possible when the water management district was given control over the Biscayne aquifer, fifty years ago. At that time, over-pumping the aquifer was recognized as the primary cause of salt water intrusion. The threat of rising sea level was in the future. Today, sea level rise is accelerating rapidly. Large areas of the aquifer will be inundated within the next thirty years. An increase in competition for a shrinking freshwater resource is inevitable.
The greatest challenge of climate change for water managers is how do we maintain cooperation and trust in the face of broken promises
The utility manager doesn’t admit it, but it is plain to see that climate change has eroded long-standing assurances that his wells will always provide the water the utility needs. Managers at the regional water management district show a similar reluctance to face the facts of climate change.
Two years ago, the US National Academy of Science delivered unwelcomed news. In light of growing knowledge about climate change, the academy said that the water management district must redirect on-going efforts to restore the iconic Everglades wetlands. This is a huge, multi-agency, intergovernmental effort that has been a major focus of the district’s activities for the past 20 years. Understandably, the district’s managers are reluctant to change course because that risks upsetting the intricate web of interagency agreements and collaborations that sustain this work.
Whether it is groundwater supplies in south Florida, ecosystem restoration in the Everglades, flood control along the Mississippi River, streamflow allocations in the western US or any number of similar situations around the world, climate change has this immediate effect on the agreements, understandings, and expectations that are the institutional machinery of water management.
Water managers have been trying to understand the implications of climate change for over thirty years. Early in my career, I studied the future impacts of climate change on water resources across Canada. Since that time, a growing army of climatologists, geophysicists, hydrologists, and ecologists has been engaged in providing ever more accurate and more precise information on the impact of climate change on elements of the hydrologic cycle: precipitation, evaporation, soil moisture, aquifer recharge, and water stored in groundwater, lakes and ice.
However, I suggest that the greatest challenge of climate change for water managers is this – how do we maintain cooperation and trust, which are essential when sharing a limited resource, in the face of broken promises, which are now inevitable.