droughts
DROUGHT DETERMINATIONS: The Commonwealth uses five parameters to assess drought conditions. These include streamflows (compared to the same time for the period of record); precipitation (departure from normal, 30 year average precipitation); reservoir storage levels in a variety of locations (especially three New York City reservoirs in upper Delaware River Basin); groundwater elevations in a number of counties (comparing to past month, past year and historic record); and Palmer Drought Index, a measure of soil moisture computed by the National Weather Service. Phases of drought preparedness in Pennsylvania are:
DROUGHT WATCH: A period to alert government agencies, public water suppliers, water users and the public regarding the onset of conditions indicating the potential for future drought-related problems. The focus during this stage is on increased monitoring, awareness and preparation for response if conditions worsen. A request for voluntary water conservation is made. The objective of voluntary water conservation measures during a drought watch is to reduce water uses by 5% in the affected areas. Because of varying conditions, individual water suppliers or municipalities may be asking for more stringent conservation actions.
DROUGHT WARNING: This phase prepares for coordinated response to imminent drought conditions and potential water supply shortages and initiates concerted voluntary conservation measures to avoid or reduce shortages, relieve stressed sources, develop new sources, and if possible forestall the need to impose mandatory water use restrictions. The objective of voluntary water conservation measures during a drought warning is to reduce overall water uses by 10-15% in the affected areas. Because of varying conditions, individual water suppliers or municipalities may be asking for more stringent conservation actions.
DROUGHT EMERGENCY: This stage is a concentrated management phase of operations to marshal all available resources to respond to actual emergency conditions, to avoid depletion of water sources, to assure at least minimum water supplies to protect public health and safety, to support essential and high priority water uses and to avoid unnecessary economic dislocations. It is possible during this phase to impose mandatory restrictions on nonessential water uses that are provided for in 4 PA Code Chapter 119, if deemed necessary and if ordered by the Governor of Pennsylvania. The objective of water use restrictions (mandatory or voluntary) and other conservation measures during this phase is to reduce consumptive water use in the affected area by 15%, and to reduce total use to the extent necessary to preserve public water system supplies, to avoid or mitigate local or area shortages, and to assure equitable sharing of limited supplies.
Drought produces a complex web of impacts that spans many sectors of the economy and reaches well beyond the area experiencing physical drought. This complexity exists because water is integral to our ability to produce goods and provide services.
Impacts are commonly referred to as direct or indirect. Reduced crop, rangeland, and forest productivity; increased fire hazard; reduced water levels; increased livestock and wildlife mortality rates; and damage to wildlife and fish habitat are a few examples of direct impacts. The consequences of these impacts illustrate indirect impacts. For example, a reduction in crop, rangeland, and forest productivity may result in reduced income for farmers and agribusiness, increased prices for food and timber, unemployment, reduced tax revenues because of reduced expenditures, increased crime, foreclosures on bank loans to farmers and businesses, migration, and disaster relief programs. Direct or primary impacts are usually biophysical. Conceptually speaking, the more removed the impact from the cause, the more complex the link to the cause. In fact, the web of impacts becomes so diffuse that it's very difficult to come up with financial estimates of damages.