Capturing Rainfall to Buffer the Impacts of Flooding and Drought By Rebecca L. Schneider, Ph.D. Dept. Natural Resources, Cornell University
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ew York is favored by a wealth of water resources, including roughly 40 inches of rain per year, 8000 lakes, 55,000 miles of rivers and coasts along the Great Lakes, Long Island Sound, and the Atlantic Ocean. They provide a plentiful supply of freshwater to support humans and an abundance of aquatic life, which in turn drives commercial fisheries, both fresh and estuarine. They support boating, swimming and other recreational pursuits for local residents and fuel the tourism industry. The interconnected network of rivers, canals and lakes form an aquatic shipping highway that connects the Atlantic to the western U.S. Lake shoreline properties are highly valued and translate into critical local tax dollars. Arguably these water riches form the foundation of the economic vitality and psychological well-being of New York’s communities. In general, New Yorkers take full advantage of this wealth, but perhaps they also take it a bit for granted. Certainly there is considerable negative public attention when an excess of rainfall causes flooding along rivers and streams. It’s understandable, as flooding impacts range from the minor inconvenience of road detours and flooded basements up to the devastating impacts of destroyed buildings, businesses and loss of life. Catastrophic damages from flooding are surprisingly not uncommon in New York, with an average of 50 million dollars spent per year in federal emergency relief, in the years prior to Hurricane Sandy1. Delaware County was the most extreme, with catastrophic flood relief required for 12 events in as many years. Although less common, extended periods without rain also create problems, translating to drought, lowered groundwater tables, and depleted reservoirs. Only about 2% of New York’s crops are irrigated 2, and so even a short interval without rain can have big impacts if it occurs at a critical time during plant growth. As an example, NY State farmers in 2012 received “10-99 million dollars for drought / heat-related crop losses.” 3
New York’s Fluid Future The extreme conditions of both flooding and droughts are likely to increase in frequency and magnitude due to climate change. The Northeastern U.S. has seen a 74 % increase in the high intensity rainfall events in the past several decades. 4 We are experiencing earlier springs and longer growing seasons, and summer temperatures are likely going to warm .5 These conditions, combined with the potential for longer intervening periods between rains, will lead to reduced base flow in streams, drier soils, and associated stress of both crops and natural ecosystems.
This synopsis needs to be put in a broader, national and global framework. The world is at a critical transition point, with water replacing energy as the most limiting resource globally. Nearly two billion people experience chronic water scarcity, which can “fuel conflict and even threaten peace.”6 and Californians are in the midst of the worst drought in decades. In this context, the water abundance of the Northeast U.S. seems an undervalued luxury. New York would benefit from adjusting its mindset with appropriate tailoring of its water management policies. We will need improved water management to reduce New York’s vulnerability to both floods and droughts in the coming decades. But viewed more broadly, several future scenarios are possible. Outside communities and businesses already recognize the incredible value of freshwater. The expenses of transporting water long distances is becoming more financially viable, as evidenced by the 1998 permit request to transport Great Lakes water to Asia, i.e. the catalyst for the creation of the Great Lakes Charter Compact (2008). Alternatively, agriculture and other water-demanding industries will be incentivized to relocate to New York. There are too many examples like the over-allocation of the Colorado River and the Aral Sea disappearance which demonstrate how inadequate planning can drain or damage even plentiful water resources. Conversely, with a sustainabilitybased underpinning, proactive planning for our water resources should make New York more resilient and lead to new economic opportunities.
WATERSHED MANAGEMENT
“Re-plumbing” Watershed Drainage Networks:
New York’s current water management and regulatory systems reflect the historic profusion of freshwater. Costs for water are incredibly cheap, with no tiered system of pricing based on amount or type of use. Aging infrastructure translates to leaks and losses of as much as 50% of piped water but no one’s counting when the source is effectively unlimited. Most public supply reservoirs have a system of rule curves to enact water conservation during droughts, however many do not. Recent adoption and expansion of the 100,000 gal/ day reporting requirement will help provide some protection for aquifers and river systems.7 However, there is no consistent statewide program for groundwater withdrawal permitting or monitoring. As a result, overdraft and groundwater depletion on Long Island is estimated at “<3 km3 between 1900 and 2008.” 8A We need to develop a water management policy and program that reflects the true value of freshwater to New Yorkers.
What New York Can Do One of the critical components is how we deal with stormwater Continued on page 36 www.nysac.org 35