Lake Lahontan was a large endorheic prehistoric lake during the Pleistocene that occupied modern northwestern Nevada and extended into northeastern California and southern Oregon . The area of the former lake is a large portion of the Great Basin that borders the Sacramento River watershed to the west.
17-543: Lahontan can refer to: Lake Lahontan Lahontan Valley Lahontan Dam Lake Lahontan (reservoir) Louis-Armand de Lom d'Arce de Lahontan, Baron de Lahontan Lahontan State Recreation Area Lahontan, Pyrénées-Atlantiques , a commune in the Pyrénées-Atlantiques département of France Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with
34-711: Is a computer simulation developed for the Truckee River to analyze water quality impacts from land use and wastewater management decisions in the Truckee River Basin. This area includes the cities of Reno and Sparks, Nevada as well as the Lake Tahoe Basin. The model is historically and alternatively called the Earth Metrics Truckee River Model . Since original development in 1984-1986 under contract to
51-505: Is evidenced by tufa formations throughout the area. Surprisingly, the watershed feeding Lake Lahontan is not thought to have been significantly wetter during its highstand than it is currently. Rather, its desiccation is thought to be mostly due to increase in the evaporation rate as the climate warmed. Recent computer simulations (using the DSSAM Model and other techniques) indicate, if precipitation and evaporation rates within
68-504: The U.S. Environmental Protection Agency (EPA), the model has been refined and successive versions have been dubbed DSSAM II and DSSAM III. This hydrology transport model is based upon a pollutant loading metric called Total maximum daily load (TMDL). The success of this flagship model contributed to the Agency's broadened commitment to the use of the underlying TMDL protocol in its national policy for management of most river systems in
85-558: The United States . The Truckee River has a length of over 115 miles (185 km) and drains an area of approximately 3120 square miles, not counting the extent of its Lake Tahoe sub-basin. The DSSAM model establishes numerous stations along the entire river extent as well as a considerable number of monitoring points inside the Great Basin 's Pyramid Lake , the receiving waters of this closed hydrological system. Although
102-608: The diel cycle and also allowed inclusion of analyzing particulate nitrogen and phosphorus. In developing DSSAM III several changes in the model operation and scope were performed. Numerous different uses of the model have been made including (a)analysis of public policies for urban stormwater runoff, (b) researching agricultural methods for surface runoff minimization, (c) innovative solutions for non-point source control and d)engineering aspects of treated wastewater discharge. Regarding stormwater runoff in Washoe County ,
119-667: The Reno-Sparks Wastewater Treatment Plant was proposed, the EPA decided to fund a large scale research effort to create simulation software and a parallel program to collect field data in the Truckee River and Pyramid Lake. For river stations water quality measurements were made in the benthic zone as well as the topic zone; in the case of Pyramid Lake boats were used to collect grab samples at varying depths and locations. Earth Metrics conducted
136-527: The algal communities are given a separate population dynamic in each river reach (e.g.metabolic rate based upon river temperature). Sources throughout the watershed include non-point agricultural and urban stormwater as well as a multiplicity of point source discharges of treated municipal wastewater effluent. Subsequent to the first generation of DSSAM model development, calibration and application, later refinements were made. These augmentations to model functionality focussed on increased flexibility in modeling
153-649: The location of the present Carson Sink . Near present day Pyramid Lake the depth of the lake was then about 900 feet (270 m) and 500 feet (150 m) at what is present day Black Rock Desert . Lake Lahontan, during this most recent glacial period , would have been one of the largest lakes in North America . Climate change around the end of the Pleistocene epoch led to a gradual desiccation of ancient Lake Lahontan. The lake had largely disappeared in its extended form by about 9,000 years ago. As
170-591: The region is sparsely populated, it is important because Lake Tahoe is visited by 20 million persons per annum and Truckee River water quality affects at least two endangered species: the Cui-ui sucker fish and the Lahontan cutthroat trout . Impetus to derive a quantitative prediction model arose from a trend of historically decreasing river flow rates coupled with jurisdictional and tribal conflicts over water rights as well as concern for river biota. When expansion of
187-476: The software development for the first generation computer model and collected field data on water quality and flow rates in the Truckee River. After model calibration, runs were made to evaluate impacts of alternative land use controls and discharge parameters for treated effluent . The DSSAM Model is constructed to allow dynamic decay of most pollutants; for example, total nitrogen and phosphorus are allowed to be consumed by benthic algae in each time step, and
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#1732765106626204-401: The specific elements within a new xeriscape ordinance were analyzed for efficacy using the model. For the varied agricultural uses in the watershed, the model was run to understand the principal sources of adverse impact, and management practices were developed to reduce in river pollution. Use of the model has specifically been conducted to analyze survival of two endangered species found in
221-611: The surface elevation dropped, the lake broke up into series of smaller lakes, most of which rapidly dried up, leaving only a playa . These playas include the Black Rock Desert , the Carson Sink , and the Humboldt Sink . The only modern remnants existing as true lakes are Pyramid Lake and Walker Lake . Winnemucca Lake has been dry since the 1930s and Honey Lake periodically desiccates. The ancient shoreline
238-496: The title Lahontan . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Lahontan&oldid=1226334133 " Categories : Disambiguation pages Place name disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Lake Lahontan The lake
255-514: The waters of Lake Lahontan, feeding on native chub and sucker . This subspecies of cutthroat trout survives today in tributary rivers of the Great Basin , and has been reintroduced to Pyramid Lake and Walker Lake after being extirpated during the 20th century. 39°48′N 118°30′W / 39.8°N 118.5°W / 39.8; -118.5 DSSAM Model The DSSAM Model (Dynamic Stream Simulation and Assessment Model)
272-463: The watershed were maintained at their historical yearly maximum and minimum, respectively, and if diversions of the Truckee River ceased, the Ice Age extent of Lake Lahontan might return. Archaeological evidence along the shore indicates the existence of the lake coincided roughly with the first appearance of humans in the region. The Lahontan cutthroat trout evolved as a predator species within
289-615: Was named by Clarence King during the Geological Exploration of the Fortieth Parallel . The name honors Louis-Armand de Lom d'Arce de Lahontan, Baron de Lahontan , a French soldier and explorer. At its peak approximately 12,700 years ago (during a period known as the Sehoo Highstand), the lake had a surface area of over 8,500 square miles (22,000 km ), with its largest component centered at
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