The discharge from Lake Mälaren is regulated to keep the lake Water level within limits set by a water decree. Despite this, in the year 2000 the lake Water level rose above the upper limit. Studies conducted at the climate modeling unit Rossby Centre at the Swedish Meteorological and Hydrological Institute (SMHI) indicate that the inflow to the lake may increase in the future. A flood in the area will, among other things, strike infrastructure and residential districts.The aim of this study was to investigate the Water levels of Lake Mälaren in future climates. In addition to this possible future expansion of the lake discharge though the sluice gates in order to keep Water levels below limits set by the water decree and to prevent flooding of the shoreline were discussed.

The Water level of Lake Mälaren has been regulated since the 1940?s. A recentinvestigation suggests that the current regulation needs to be adjusted in order toprevent a decline in Water level, salt water from infiltrating from Lake Saltsjön,and risk of floodings. In addition to these preventions, the new regulation couldpotentially effect the natural environment and agriculture practices in the lowlands that surround the lake. The new regulation proposal calls for an increase invariations in Mälaren?s Water level during seasons, while the annual mean waterlevel will remain the same.

This report consists of  an anlysis of the imapct of a dam failure at Tjärnviksdalen in Ragunda, Sweden. The analysis is conducted using the EU model for environmental impact assessments, as well as a group interview. The presentation of the results in the form of a map  where the Water level has been raised to the level that the County Board  of Jämtland considers to be possible in case of a dam failure.The result of this work is a detailed analysis of the consequenses that a dam failure would cause, the result consider everything from the direct consequences of the water column to an analysis of the chemical changes that the water would undergo.Parts of the analysis have shown that the purification centre and the old deposits will have the biggest impact on Hammarstrand. Both the purification centre and the deposits will realise chemicals to its nearest environment and because of the flooded purification centre the city will not have the ability to clean the water. .

This report is about the experiments with mixing of the separated water and the vacuum pump seal water at Hellisheiði power plant. This is done to prevent silica scaling and clogging in pipes and reinjection wells as well as eliminating vacuum pump seal water from the plant. The experiments were done in four stages: the first stage comprised of tests with different flows of separated water at 70°C, the second stage was carried out by mixing the separated water at 70°C and the seal water with different amounts of the seal water, the third and the fourth stages were like the first and second but with the separated water at 120°C. The results show that this method is good if the mixture is around 50/50 separated water and seal water, to control the silica scaling in the separated water and to be able to reinject the seal water with the separated water. This does not eliminate the silica scaling in all of the separated water because the amount of separated water is much more than the amount of seal water that comes from the plant. .

Nanofiltration is a proper way of preparation of drinking water. The process has a lot in common with reverse osmosis where a semipermeable membrane is used to separate a pure water flow from the remaining water. A pilot plant was used to ensure that nanofiltration is a suitable technology for a specific waterworks station in Glemmingebro, Ystad. The purpose was also to find out if a pH-adjustment is needed for feed water in a possible full scale plant.  In this case nanofiltration is used mainly to remove sulphate and calcium since the raw water contains concentrations of these substances which exceed the limits for potable water. It is important to receive a high recovery (RC), otherwise the deliviery of water won?t be high enough.

Periods of hypoxia are a recurring issue in Brunnsviken. Main factors that trigger hypoxia in Brunnsviken are eutrophication  due to anthropogenic emission of nutrients, stratification in the water column due to salinity and temperature differences  that prevents mixing and a sill inlet that prevents water exchange. As an attempt to improve the oxygen levels, bottom water is pumped from Brunnsviken causing aerated surface water to flow back into the basin.  The objective of this Master?s thesis was to study the change in dissolved oxygen levels due to pumping.

The focus of this project has been on the drainage tank of the reheater on Ringhals 1. This tank has on two previous occasions received such a high Water level that the system automatically emergency stopped. For this reason, events and various readings from these two occasions has been specifically studied and analyzed. In order to prove theories about what causes these problems a model of the system was created in the program Dymola. Using simulation results from the model, we have been able to demonstrate how the system's measured values should look likeunder normal conditions with respect to flows, pressures, temperatures, valve positions and Water level in the drainage tank.

The purpose of this master thesis was to study the water system for mechanically cleaned water at Skärblacka mill, in order to find and evaluate possibilities of using energy more efficiently. The thesis also includes an evaluation of the software tool ?Pumpanalys?Skärblacka mill produces pulp and paper. The large amount of water required is cleaned mechanically through filters and called mechanically cleaned water (MR0). The MR0 water is pumped out to the factory by four crude water pumps.

Hydropower is an important source of energy in Sweden and accounts for about 46 % of the total energy production. Sweden has about 1 200 hydropower plants and with the intention of raising the pressure head of the water and to store water, dams are built by the power plants. The storage reservoirs make it possible to adjust the energy production by demand and season. Dams in connection to the reservoirs are subjected to additional loading during periods of high floods or when an icecap in the winter is formed on the reservoirs. In order to maintain the dam safety, the power companies in Sweden are working with guidelines for dam safety from RIDAS.

Nanofiltration is a proper way of preparation of drinking water. The process has a lot in common with reverse osmosis where a semipermeable membrane is used to separate a pure water flow from the remaining water. A pilot plant was used to ensure that nanofiltration is a suitable technology for a specific waterworks station in Glemmingebro, Ystad. The purpose was also to find out if a pH-adjustment is needed for feed water in a possible full scale plant.  In this case nanofiltration is used mainly to remove sulphate and calcium since the raw water contains concentrations of these substances which exceed the limits for potable water. It is important to receive a high recovery (RC), otherwise the deliviery of water won?t be high enough.

We all know that water is very important for both animals and humans. When we are weaning the piglets from the sow we must guarantee that the piglets can start to drink more water instead of sow milk. The first thing to check is always the quality of the water that is to be used. To secure that, you must take a water sample. If the water is inadequate it can bring a lot of problems and diseases.

Severe floods caused by heavy autumn rains in year 2000 raised the question whether measures to reduce the damage from high Water levels, in the area surrounding lake Glafsfjorden and along the river Byälven down to lake Vänern, are possible. One option is to reduce flow resistance along the river and thereby lower the maximum Water level a given inflow would cause. Good knowledge of hydraulic and hydrological conditions is necessary in order to estimate the effect of such flow-reducing measures. In order to quantify such effect a 1-dimensional hydraulic flow model has been set up for the river Byälven using the software package MIKE 11. The model is more detailed, especially concerning topography and bathymetry, than earlier models used for studies of the river.

In recent years, existing solutions for cooling personal computer CPUs have been supplemented by a new product category, factory sealed water cooling loops. These systems, consisting of a water block with an integrated pump, a fan and a radiator, perform well compared to the air cooling solutions but are less effective than larger, custom-built water cooling systems.This project aims to explore the most important aspects of a factory sealed system and to identify possible cost-effective enhancements of the performance.The most significant differences between the different groups of water cooling loops are the block design and the pumping power. The performance of both categories is also largely dependent on the fan power, but increasing fan power has a large negative impact on the noise level.Both radiator size and fan model choice appear, in tests, to be relatively unimportant, presuming that the noise level is kept constant. The position and direction of the fan, however, has significant impact on both the temperature and the sound level.Water blocks can be designed in several different ways, both regarding the heatsink design and the flow direction. In simulation, flow with the inlet centered above the heatsink result in considerably lower pressure drop and slightly higher temperatures than flow through the block, for heatsinks with fin arrays.Creating a competitive product in this product segment certainly seems possible, as there are performance-increasing changes to be made that seemingly has little impact on the production cost.

Water is an important food and an important natural resource. In order to protect these are the Environmental Code and the EU directive given to water protection and related water protection regulations will be established for all water sources until 2010. Those who will prepare a water protection and related water protection regulations is the municipality or person responsible for water supply. The person then decides and declares the area as water protection and related water protection regulations are municipal or provincial government. The idea of creating a water protection is to protect the water supply and the body of water against pollution caused by point sources, diffuse sources and accidents combined.

This report is presenting an approach that can be used to measure water surfaces in difficult conditions caused by dense vegetation and lack of nearby known points. The objective was to make a contribution to necessary measures for adaptation against floods in Grums Municipality along the stream Karlbergsån, which may occur when persistent rain raises the level of the stream. Along the river there are low-lying areas prone to flooding. According to Grums Municipality, the stream may widen where the Water level differences are large, to create a better flow path and to counteract flooding. Grums Municipality was also interested in survey stormwater discharges which may affect the Water level in the stream.