|Hydrologic Unit Code (HUC):||05100101|
|Datum:||448.82 feet above NAVD88|
|Drainage Area:||3,593 square miles|
|County in which site is located:||Campbell|
|Site managed by:||Louisville District Office|
The Licking River at Highway 536 nr Alexandria, Kentucky is the most downstream site on the Licking River before the confluence with Ohio River. More than 250,000 Kentuckians rely on the Licking River for drinking water. The Licking River at Highway 536 nr Alexandria, Kentucky site is 18.8 miles upstream of the Ohio River. The mouth of the Licking River is located in the mountains of Eastern Kentucky and meanders northwest until it meets the Ohio River near Newport, KY. Flow is regulated by Cave Run Lake since 1973. Watershed is highly dissected plateau with steep hillsides. Runoff can lead to a swift rise in gage height. Stream gradient is minimal between gage and Ohio River 18.8 miles downstream leading to some backwater conditions.
Discrete samples nitrate are collected at this site throughout the range of hydrologic and chemical conditions. The main objective of the discrete nitrate samples is to compute loads of nitrate.
Continuous water-quality measurements and discrete samples collected at a super gage are combined in statistical surrogate models. Models are developed to relate in-stream instrument measurements to analyzed discrete constituent concentrations. After peer review and approval, a model can be used to continuously compute constituent concentrations based upon real-time continuous water-quality measurements.
Sanitary District #1, located in Northern KY, in Cooperation with the USGS, established a stream gaging network to adhere to requirements of a Consent Decree. This legally-binding document between SD-1 and state and federal environmental regulators helps to increase responsible watershed management. The USGS has been collecting surface water and water-quality data throughout this network since 2007. Delivery of excess nutrients, primarily nitrogen and phosphorus, from the Ohio River to the Mississippi River is a potential problem. Each year, a hypoxic zone (water without dissolved oxygen) forms in the northern Gulf of Mexico that can cause fish to leave the area and that can cause stress of depth to bottom-dwelling organisms that can’t move out of the hypoxic zone. Hypoxia is believed to be caused primarily by excess nutrients delivered from the Mississippi River in combination with seasonal stratification of Gulf waters. Excess nutrients promote algal and attendant zooplankton growth. The associated organic matter sinks to the bottom where it decomposes, consuming available oxygen. Stratification of fresh and saline waters prevents oxygen replenishment by mixing of oxygen-rich surface water with oxygen-depleted bottom water. In an effort to better understand where these pollutants are originating, the USGS Ohio Kentucky Indiana WSC has become interested in what is entering and what is leaving the state of Kentucky. To accomplish this goal, each major tributary into the Ohio must be monitored. Once these Super Gages are established nutrient data collection will allow surrogate models to be created.