Emergency Spillway Research Articles

Water quality of stormwater generated from an airport in a cold climate, function of an infiltration pond, and sampling strategy with limited resources.

Monitoring pollutants in stormwater discharge in cold climates is challenging. An environmental survey was performed by sampling the stormwater from Luleå Airport, Northern Sweden, during the period 2010-2013, when urea was used as a main component of aircraft deicing/anti-icing fluids (ADAFs). The stormwater collected from the runway was led through an oil trap to an infiltration pond to store excess water during precipitation periods and enhance infiltration and water treatment. Due to insufficient capacity, an emergency spillway was established and equipped with a flow meter and an automatic sampler. This study proposes a program for effective monitoring of pollutant discharge with a minimum number of sampling occasions when use of automatic samplers is not possible. The results showed that 90% of nitrogen discharge occurs during late autumn before the water pipes freeze and during snow melting, regardless of the precipitation during the remaining months when the pollutant discharge was negligible. The concentrations of other constituents in the discharge were generally low compared to guideline values. The best data quality was obtained using flow controlled sampling. Intensive time-controlled sampling during late autumn (few weeks) and snow melting (2 weeks) would be sufficient for necessary information. The flow meters installed at the rectangular notch appeared to be difficult to calibrate and gave contradictory results. Overall, the spillway was dry, as water infiltrated into the pond, and stagnant water close to the edge might be registered as flow. Water level monitoring revealed that the infiltration capacity gradually decreased with time.

HYDROLOGICAL STUDY AND ANALYSIS FOR PROPOSED SARTIK DAM PART 2: RESERVOIR CHARACTERISTICS, SIMULATION MODEL, AND FLOOD ROUTING CALCULATIONS

This research is the part 2 of hydrological study and analysis for proposed Sartik dam which located on the Lesser Zab River, the second largest tributary of Tigris River at 18 km northeast of Altun Kopri town, within Erbil governorate of Iraqi Kurdistan Region. In this part water demand from the dam is calculated, the dam power generating facility with an installed capacity amounting to 156 MW with a maximum discharge of 300 m3/sec. The characteristics of the dam reservoir were calculated, from reservoir sedimentation calculation the dead storage level and capacity was determined and was equal to (309 m.a.s.l., and 104,304,031 m3) respectively. The monthly and annual water losses due to evaporation were calculated from daily recorded evaporation using an equation based on area, volume and elevation curve, and the annual losses were equal to (51,132.366 m3), also the normal reservoir water level (NWL) was fixed at 325 m.a.s.l. which gives live storage capacity equal to (384,846,885), and flooded area equal to (34.184 km2). The simulation model of the dam reservoir, prepared from the calculation of water inflow into the reservoir and water demand including evaporation losses. The inflow was taken for different types of water years, dry (deficit) years (1984, and 1999), average water years (1981, and 1995) inflow, and maximum (flood) water years (1969 and 1988) inflow. From the curves, it is clear that the reservoir starts full at month April and ends full at month March during one year taking into account that the maximum water storage in the reservoir is (489,150,916)m3 and minimum storage is (104,304,031) m3. The flood routing study was done using the (PMF, 1000, 100, 50, and 25) years return periods inflow hydrographs, and stage and volume curve by fixing the crest level of ogee spillway will at 320 m.a.s.l., choosing the number of gated spans equal to 7, the length of each span equal to 12m, and the initial water level of the reservoir was 325 m.a.s.l. The results of this routing will be used to determine the design parameters of the spillway and to determine the actual need of the emergency spillway.

A resilience loss assessment framework for evaluating flood-control dam safety upgrades

Dams that were designed and built decades ago may not meet current design standards that reflect our improved knowledge of extreme rainfall events. When comparing dam safety upgrades, cost-efficient options that reduce the probability of overtopping are preferred. However, these criteria neglect flood damage costs resulting from controlled water flow inherent to the design of the safety upgrades. Therefore, to address this shortcoming, we apply the concept of resilience to evaluate dam safety upgrade options from a flood damage mitigation perspective through a resilience assessment framework. In this study, resilience is defined as the ability to provide flood-control service after an extreme rainfall event and to recover a desired level of functionality as soon as practicable. This framework features four main steps: estimating the probable maximum flood for the dam under investigation, calculating the dam discharge for each of the upgrade options, quantifying the loss in system resilience, and converting the losses into monetary units. This framework is applied to two dam safety upgrade options (constructing an emergency spillway and increasing dam crest height) for a large dam in Andong, South Korea. In practice, the former option is typically preferred as it is cost-efficient. However, we find that the latter option is superior when accounting for flood damage costs caused by water that is intentionally released from the dam during a probable maximum flood event. This study will help to ensure sound decision making when evaluating dam safety upgrade options by considering not only construction costs but also flood damage costs.

Roller-Compacted Concrete Dams Rehabilitation in Terms of Different Problem

Roller-Compacted Concrete (RCC) started in the US and Canada near 30 years ago, at that time it was a new method to construct gravity dams or rehabilitated. After passing these years, it’s become one of the popular methods in designing dams and called Roller Compacted Concrete. No slump is the specific property of the concrete of RCC dams. This type of dam needs place concrete in thin layers and compacted by roller to meet the require compaction. By one side, RCC dams can dissipate energy by stair step slope more than 70 percent of water energy and from the other side, all of the ordinary dams need to have an emergency spillway, but due to using all the length of the crest for spillway in the RCC dams, it is removed and the cost of constructing decreased. One of the most common problems which occur in the RCC dams at the beginning of its usage is hairline cracks throughout dam. This kind of cracks can start from upstream to the downstream. Rehabilitations have got several options depends on the kind of cracks and situation of cracks on dams such as drill holes, injecting grout, using different type of membrane and geomembrane, covered sealing system and covered geomembrane content. In this paper, try to investigate the different rehabilitation way of RCC in detailed and specified the best way for each kind of cracks.

Site Investigation For Construction Of Emergency Spillway At The Jatigede Dam

An emergency spillway has been planned to be constructed at the Jatigede Dam, West Java, to allow floodwater to flow downstream and to prevent the capacity of the main spillway to be exceeded during large flood events. The complex geology of theJatigede Dam area, however, poses a challenge to determine the suitable location for the emergency spillway construction, either in the area to the west or to the east of the embankment dam. An engineering geological mapping and landslide susceptibilityzoning were conducted to determine the engineeringgeological characteristics of the area surrounding theJatigede Dam. The site investigation showed that thearea to the west of the embankment dam tended tohave a lower slope inclination than the area to theeast of the embankment dam. Both areas to the westand to the east of the embankment dam were found tobe composed of less erosion resistant rock units. Theexistence of the earth retaining structures for slopestabilization in the area to the east of the embankment dam will, however, likely limit the flexibility in developing the emergency spillway route. With respect to the existence of fault systems, both areas to the west and to the east of the embankment dam will likely be influenced by similar conditions. The areato the west of the embankment dam tended to be lesssusceptible to landslide as compared to the area tothe east of the embankment dam. The undevelopedland use of the area to the west of the embankmen dam as compared to the area to the east of the embankment dam will provide more flexibility in construction of the emergency spillway. Due to the morefavorable engineering geological conditions, the area to the west of the embankment dam is proposed forthe location of the emergency spillway construction.Keywords: Emergency spillway, Engineering geological mapping, Jatigede Dam

An Experimental Study on Flood Control Capability of Dry Dams Constructed in a Series

The new Cascade concept of flood control is demonstrated in laboratory experiments in which upstream dams in a series of dams constructed along a river overflow from emergency spillways while the final downstream dam is required only to use its normal spillway and never do its emergency spillway. Multiple small dry dams lacking a slide gate in a normal spillway should be constructed in a series rather than as a single large dam to prevent flood disasters and to preserve the natural environment. Dry dams for flood control have recently been reviewed, planned, and built at sites in Japan. In this paper, we compare the Cascade method to conventional flood control in laboratory experiments conducted based on the condition that dams all have the same reservoir capacity. Results have shown that the Cascade method using multiple dry dams was considerably more effective than conventional flood control. Furthermore, the additional flood control effect of a dry dam equipped with closable and openable gate in its regular spillway was experimentally confirmed although there is no such kind of the gate on an ordinary dry dam. This new dry dam should be constructed in the river’s upper reaches away from the existing downstream storage dam needing still more its capacity for water utilization, thus ensuring the amount of water available by closing the regular spillway after the dry dam is filled to capacity. The flood control capacity of dams including the new dry dam is stronger than that of an ordinary storage dam thanks to the dry dam’s storage function.

Vliv poldrů na průběh povodní v povodí Tiché Orlice

Polders show an important water-management function in the flood-control protection of watersheds. The course of actual floods in recent decades and effects of the water works on flood flows have proved the suitability of the construction within integrated flood-control measures in particular watersheds of the Czech Republic. To determine the transformation effect of flood-control measures in watersheds mathematical modelling is an important method, which is used not only in the preparation and design of retention areas but also in dealing with the flood protection of towns and villages. Easy verification of other measures in watersheds is also useful. Their implementation can be thus prepared for the future or it is possible to back off the intentions. In our case, a fact is advantageous that the model is ope­ra­ted in the workplace of the Elbe Basin water-management dispatching centre, which is compatible with assessed polders in the partial Elbe watershed, namely in the Tichá Orlice watershed and its partial Třebovka watershed. The polders assessed are situated on the Třebovka stream, which is the lar­gest tributary of the Tichá Orlice river. These dry reservoirs and the increased protective function of the Hvězda pond affect runoff from about 80 km2. Within research activities, possibilities were studied to obtain necessary retention areas in existing small water reservoirs. It became evident that the only rea­lis­tic solution was to increase protective functions of the pond Hvězda. Its present total retention space of 1.4 million m3 can be increased only by 0.35 million m3, however, in combination with the sophisticated lay-out of a new emergency spillway and outlet the whole retention space can be used much more effectively. To obtain other retention areas localities were found out in the whole upper watershed of the Třebovka stream, which fulfilled requirements for placing the adequate capacity of polders. Subsequent modifications of the Třebovka channel in the most endangered villages and towns and their capacity design according to transformation effects of selected reservoirs and measures, determination of their effect and comparison with profiles on the Tichá Orlice are the content of the paper.

Resilience Assessment of Dams’ Flood-Control Service

최근 기후변화로 인해 극한강우사상의 빈도 및 강도가 증가함에 따라 과거 기준에 의해 설계 시공되어 현재 운영 중인 댐의 수문학적 안전성에 의문이 제기되고 있다. 이에 따라 댐을 증고하거나 여수로를 확장/신설하는 방안이 추진되고 있는데, 이러한 대안을 선정할 때 월류 가능성에 매몰된 나머지 하류 홍수피해를 간과하는 경향이 있다. 이에 본 연구는 회복탄력성의 개념을 도입해 종합적인 홍수조절기능의 관점에서 댐의 안전성 강화 대안을 평가할 수 있는 프레임워크를 제시하였다. 제시된 프레임워크를 활용해 기 수행된 사례에 적용한 결과 각 대안에 따른 홍수유출특성이 선정과정에서 중요한 요소로 평가되어야 함을 확인할 수 있었다. Recently, due to the climate change, the frequency and intensity of extreme rainfall events have been continuously increased in regions of South Korea. As a consequence, safety issues have been raised especially in the hydrologic safety of old dams designed and constructed by the old standards. In general, for improving hydrologic safety of existing dams, two options are considered: 1) raising dam crest; and 2) constructing or expanding an emergency spillway. In this process, the main criteria of alternative selection are overtopping possibility and cost efficiency of each alternative. This approach is easy to implement but it is subject to major limitation for the proper evaluation of alternatives, overlooking downstream flood damages by any controlled flow of water that is intentionally released from dams to eliminate the possibility of overtopping. Therefore, this study suggests a framework for evaluating the dam safety strengthening alternatives in terms of a comprehensive flood control by applying the concept of resilience. The case study shows that the resilience-based evaluation framework which considering downstream flood damages is effective in the selection of dam safety strengthening alternatives.

直列配置された流水型ダム群の洪水制御能力の検討

A new flood control concept called 'Cascade method' which permits a dam to overflow from an emergency spillway around an upstream region with plural dams set in series in a river basin has been suggested. In this study, characteristics of the new flood control method are investigated for various inflow flood hydrographs whose shape is transformed systematically. As a result of this study, it is made clear that the new method can control more effectively for leaning forward inflow hydrographs. In addition, we propose another new type of a dry dam to encourage water-utilization. The new type has an outlet work for flood control with a slide gate which can be closed automatically depending on hydraulic pressure or buoyancy. We call this gate 'pressure gate'. The new type of dry dams constructed in series with a pressure gate strengthens still more flood control capability of the Cascade method.

Protecting roller-compacted concrete armored emergency spillway against uplift with geocomposite drain: Loxahatchee Reservoir example

ABSTRACT: When designing a roller-compacted concrete (RCC) spillway for a reservoir, seepage-induced uplift pressures need to be considered. This case study describes the design, construction and post-construction performance of a drainage system consisting of a geocomposite drain immediately beneath a stair-stepped RCC spillway at the Loxahatchee Reservoir in western Palm Beach County, Florida, USA. The installation comprised 2.8 km of RCC and a geocomposite drain to construct the fixed-weir emergency spillway. The primary stability issue for the spillway was the development of excessive pore water pressure beneath the RCC in the event of rapid drawdown of the reservoir. Transient seepage analysis predicted that installation of the geocomposite drain would eliminate excess pore pressures beneath the RCC, and dramatically increase the factor of safety against uplift (increased from 0.5 to a value of the order of 6), preventing structural instability of the spillway. Since placing the reservoir in operation, no structural instability has been observed in the spillway. Also, the absence of excess pore pressure is predicted by post-construction transient seepage analysis using reservoir operational-stage data.

Discussion of “Stop Logs for Emergency Spillway Gate Dewatering” by Derek R. Freckleton, Michael C. Johnson, M. Leslie Boyd, and Dustin G. Mortensen

Discussion of “Stop Logs for Emergency Spillway Gate Dewatering” by Derek R. Freckleton, Michael C. Johnson, M. Leslie Boyd, and Dustin G. Mortensen

Discussion of “Stop Logs for Emergency Spillway Gate Dewatering” by Derek R. Freckleton, Michael C. Johnson, M. Leslie Boyd, and Dustin G. Mortensen

Discussion of “Stop Logs for Emergency Spillway Gate Dewatering” by Derek R. Freckleton, Michael C. Johnson, M. Leslie Boyd, and Dustin G. Mortensen

Closure to “Stop Logs for Emergency Spillway Gate Dewatering” by Derek R. Freckleton, Michael C. Johnson, M. Leslie Boyd, and Dustin G. Mortensen

Closure to “Stop Logs for Emergency Spillway Gate Dewatering” by Derek R. Freckleton, Michael C. Johnson, M. Leslie Boyd, and Dustin G. Mortensen

An Experimental Study for Construction of Emergency Spillway in Daechung Dam

Recently, the flood frequently happened by several effects, such as El Nino et al., is the meteorological accident to attack the stability of dam. Hence, it was necessary to increase the stability of existing dam and dam design criteria were reinforced with probable maximum flood. This study was conducted in order to install the emergency spillway in Daechung Dam. Daechung Dam is located in the upper course of Guem River, in the middle of Korea, near a Sobak mountain range. The stream length and area of Daechung Dam are each about 401 km, about 9886 km2. According to the Report of new training project in Daechung Dam published in 2004 year, Maximum flood water level of Daechung Dam was calculated EL. 84.18 m increased of previous maximum flood water level (EL. 83 m). The aim of this study is to make an alternative plan on problems predicted by analysis of experimental data which is the results on the hydraulic model on dam structures. Analysis of experimental results was classified dam structures, such as approach channel, spillway, energy dissipater and stream, by design conditions.

Stop Logs for Emergency Spillway Gate Dewatering

Emergencies resulting in uncontrolled flow through spillway gates often lead to millions of dollars lost to repairs, lack of dam productivity, property damages, and risks to public health and safety. A considerable need exists for reliable emergency dewatering systems to prevent these consequences. Stop logs are the most commonly used dewatering system for spillway gates but are typically designed for maintenance purposes only. They have been found in most cases to be unreliable for emergency closure under flowing conditions. Considering the economic advantages a dewatering system would provide were it functional for the dual purposes of maintenance as well as emergency closure, a new stop log design was developed. This study assesses the design that enables deployment under no-flow conditions as well as flowing, or emergency conditions. The information found in this study provides dam owners, operators, and engineers with options to reduce damages resulting from uncontrolled releases owing to partial or complete failure of spillway gates, including the failure of gates to close after having been raised.

Comprehensive Foundation Rehabilitation at Bear Creek Dam

Research Article| August 01, 2010 Comprehensive Foundation Rehabilitation at Bear Creek Dam JOHN E CHARLTON; JOHN E CHARLTON 1Paul C. Rizzo Associates, 101 Westpark Boulevard, Suite B, Columbia, SC 29210 1Corresponding author email: john.charlton@rizzoassoc.com. Search for other works by this author on: GSW Google Scholar CONRAD GINTHER; CONRAD GINTHER 1Paul C. Rizzo Associates, 101 Westpark Boulevard, Suite B, Columbia, SC 29210 Search for other works by this author on: GSW Google Scholar DONALD A BRUCE DONALD A BRUCE 2Geosystems, L.P., P.O. Box 237, Venetia, PA 15367 Search for other works by this author on: GSW Google Scholar Environmental & Engineering Geoscience (2010) 16 (3): 211–227. https://doi.org/10.2113/gseegeosci.16.3.211 Article history first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation JOHN E CHARLTON, CONRAD GINTHER, DONALD A BRUCE; Comprehensive Foundation Rehabilitation at Bear Creek Dam. Environmental & Engineering Geoscience 2010;; 16 (3): 211–227. doi: https://doi.org/10.2113/gseegeosci.16.3.211 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyEnvironmental & Engineering Geoscience Search Advanced Search Abstract The Tennessee Valley Authority (TVA) Bear Creek Dam is a high-hazard potential embankment dam in northwest Alabama that provides water supply, flood control, and recreation benefits. Since its initial filling in 1969, the dam has experienced significant seepage through its karst limestone foundation. After experiencing limited or temporary success at controlling seepage using supplemental grouting programs and downstream seepage collection systems, TVA elected to embark on an extensive rehabilitation effort for the existing dam's deficiencies, as follows: (1) foundation seepage leading to a potential loss of embankment material at the foundation contact and (2) the potential loss of the embankment dam as a result of overtopping during the potential maximum flood (PMF). Paul C. Rizzo Associates, Inc., was hired to design a permanent solution for the dam's deficiencies. Performance of this rehabilitation consists of construction of a downstream roller-compacted concrete reinforcement structure to prevent loss of the dam during PMF overtopping and installation of a composite seepage barrier consisting of a two-line grout curtain with cutoff wall panels at select locations to reduce potentially hazardous foundation seepage. The existing emergency spillway as well as the existing sluiceway tunnel and associated intake structure were preserved as a part of this new construction. This article presents the means and methods employed to effectively treat the karst limestone geology present at the Bear Creek Dam, with emphasis on the evolving nature of the design and construction of the final seepage barrier, whereby continuous, ‘real-time’ evaluation of the geologic conditions encountered during each phase of the foundation treatment process was used to tailor the scope and design of the next step of the rehabilitation. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Ka Loko Dam Break

On March 14, 2006, the Ka Loko Dam broke on the North Shore of Kauai, Hawaii, sending millions of gallons of water downstream. Seven people were killed and dozens of homes and properties were damaged. Multiple parties faced liabilities for the disaster, including the owner of the dam, the State of Hawaii, and the County of Kauai. This paper aims to provide information regarding the history of the dam and a discussion of the case issues. The owner faces charges for the disaster because he allegedly filled an emergency spillway, although no direct observations of him doing so exist. The State of Hawaii came under scrutiny for the break because they failed to follow their own regulations regarding dam inspections. The state was also vulnerable because water originating on state lands was being diverted to the Ka Loko Reservoir at the time of the break. The County of Kauai was accountable because it did not properly manage illegal construction activities by the owner that probably led to the filling of the sp...

Technical Note: Rehabilitation of a Biofouled Pressure-Relief Well Network, Garrison Dam, North Dakota

Dams are subject to seepage through their foundations and abutments. Seepage may result in excess fluid pressures or uplift pressures beneath elements of the dam, thereby becoming a safety concern with respect to the stability of the dam. Pressure-relief wells are an integral part of a dam's seepage control system. These wells are generally designed to be free flowing and placed to intercept zones in dam foundation materials that are sensitive to elevated fluid pressures. Pressure-relief wells reduce excess fluid pressures by allowing water to be safely discharged from the zone affected by the excess fluid pressure (U.S. Army Corps of Engineers [USACE], 1992). Upon completion of review of historic pressure-relief well discharge rates and down-hole video camera observations for a pressure-relief well network (Figure 1) at Garrison Dam, ND, it was determined rehabilitation efforts were required. Rehabilitation methodology and results for this pressure-relief well network are presented in this paper. Figure 1. Location of the pressure-relief well network and associated piezometers at Garrison Dam, ND (1 ft = 0.3048 m). Garrison Dam and reservoir (Lake Sakakawea) comprise a multiple-purpose project consisting of a rolled earth-filled dam, an emergency spillway, and a hydroelectric-generating plant. The reservoir stretches 178 mi (286 km) and has a capacity of 2.3 million acre-ft (2.8 billion m3) for flood control, conservation, navigation, power development, irrigation, recreation, and other uses. The dam is 11,300 ft (3,440 m) long; 210 ft (64 m) high; 60 ft (18 m) wide at the top; and 2,600 ft (790 m) wide at the base. Construction on the dam began in 1947 and lasted 7 years. Reservoir filling began in 1953, and the minimum operating pool was reached in 2 years and 5 months. The pressure-relief well network consists of eight pressure-relief wells, each 6 in. (15 cm) in diameter, …

Planning and Design of Cost-effective Water Harvesting Structures for Efficient Utilization of Scarce Water Resources in Semi-arid Regions of Rajasthan, India

Water-harvesting structures have the potential to increase the productivity of arable lands by enhancing crop yields and by reducingthe risk of crop failure in arid and semi-arid regions, where water shortages are common because of scanty rainfall and its uneven distribution. In semi-arid regions of Rajasthan, India, existing practice of harvesting rainwater is through anicut and earthen embankments. Because of higher costs and higher technical skills involved in the construction of these structures, these structures have not been accepted by the resource-poor local people. Therefore, in the present paper, the detailed design of some low-cost water-harvesting structures using locally available materials and adaptable to the socio-economic conditions of the beneficiaries is discussed. Two types of cost-effective water-harvesting structures, which include dry stone masonry and upstream-wall cement masonry of heights 1, 2, and 2.5 m for catchments of less than 10, 10 to 20, and 20 to 30 ha, respectively are proposed and designed. The analysis of costs involved in constructing dry stone masonry and upstream-wall cement masonry water-harvesting structures, emergency spillway, anicuts and earthen embankments revealed that the earthen embankments have the least cost of construction whereas the anicuts have the highest construction costs for all the selected heights. However, based on the past experiences, earthen embankments are not suitable for the semi-arid regions of Rajasthan. The economic evaluation of the proposed structures indicated that the dry stone masonry structures are very cost-effective for the region with a benefit-cost ratio of 3.5:1 and the net present worth value of Rs. 102978. Although the economic indicators ranked the upstream-wall cement masonry structures lower than the dry stone masonry structures, the former has greater stability and strength compared to the latter. In practice, both the cost-effective water-harvesting structures (i.e., dry stone masonry and upstream-wall cement masonry) are gaining wide acceptance and popularity in the region through some nongovernmental organizations, which have adopted the design presented in this paper.

Remote sensing of temporal and spatial variations in pool size, suspended sediment, turbidity, and Secchi depth in Tuttle Creek Reservoir, Kansas: 1993

Four dates of Landsat Thematic Mapper data from 1993, April 9, July 30, August 15, and September 16, were used to assess temporal and spatial patterns of lake area and dimensions of suspended sediment concentration in Tuttle Creek Reservoir, Kansas. In 1993, excessive precipitation in the Big Blue River Basin, and throughout much of the Upper Middle West, led to widespread flooding. Rains produced substantial erosion, sediment movement down the stream network, and a runoff volume that filled Tuttle Creek Reservoir, a U.S. Army Corps of Engineers flood control structure. The April 9 data are from before the flood, the July 30 data are from the time of maximum pool size and use of the emergency spillway, and the August and September data document the declining pool sizes. Three separate analyses were performed on each of the four dates of Thematic Mapper data. One set of analyses involved applying an existing physical model that uses at-satellite reflectance for TM Band 3 to estimate variations in suspended sediment, turbidity, and Secchi depth throughout the reservoir. Maps of estimated parameters of water quality for the four individual dates were compared and analyzed to document spatial and temporal changes. The second research method involved unsupervised classification (ERDAS ISODATA algorithm) of the data from the Tuttle Creek Reservoir. Water areas were grouped into coherent classes for further spatial analysis using a two-step or layered classification procedure for each date. The third analysis used a GIS overlay technique to compare the area of the water surface for each of the four dates with the flood pool as marked on U.S.G.S. 7-1/2 minute quadrangles. Comparisons document the major change in lake area between April and July, the high levels of suspended sediment in mid-summer, and the decline in pool size and concentrations of suspended sediment by mid-September. The study illustrates the advantages of using remote sensing to assist in documenting a relatively short-term environmental hazard. This study also demonstrates the value of Landsat Thematic Mapper data for use in mapping geographic variations in water area and quality in conjunction with a major flood event.