Perhaps you can find some past data, aerial photos, or local residents that can help from their memory or pictures of conditions. Lake management, uses for irrigation may also be considered. Timing of urbanization, conversion of land use, timing of industrial and housing development, waste disposal methods, release of various pollutants in the past would affect water and lake quality, but finding actual data may be difficult, and all you might muster is compiling some relative information that can be used to estimate. Predicting future can also be difficult unless there are some trend data and ability to control pollutants, management, environmental factors. In some instances, all it takes is a slight shift in chemistry or conditions such as a few dry years from having a balanced population of green algae and other biota in lake to one with noxious blue green algal blooms, and mortality to signifacant portions of lake life. Lake temperature can also be a factor, and headwaters that have removed forest buffers are going to warm. Reversing effects to lakes can be costly, so best to catch potential issues early and work to find measures to help limit, minimize or mitigate pollutants. Some added options may exist if lake water levels can be controlled through designed releases and flushing of some pollutants that may influence downstream resources.

Getting representative samples of lake water quality may also present some difficulties, as some pollutants adhere to sediments that tend to deposit in upper lake margins from or associated with pollutant sources. If possible, coordinating with experienced limnology, hydrology, aquatic biology and microbiology, meteorology, civil engineering and analytical chemistry skills may all have some contributions to help address some of the varied aspects of this problem. Acid rain, low alkalinity waters, low pH from pine forests, aquatic life, invasive species, rangelands, pets, population, industry, agriculture and urban lands are just a few of the potential areas of consideration.

The desired predictive answers would be difficult to achieve with reliability, even with substantial effort by experienced professionals and the ability to respond, control or manage conditions. Lake type and conditions can make some differences. Shallow lakes, that happen to have low pH, low alkalinity, moderate to high temperatures, low dissolved oxygen, turbidity issues from certain clays, are examples of problem areas that are in addition to pollution sources. The inverse of these conditions may suggest a lake with more potential capacity and resilience and management ability to the limit the effects of pollutants.

Dear Nega,

The question you asked depend on the region of your study location. If its under the government authorities they may analyze water quality for determine the current condition of quality of water regularly. Further, some publications have raw data or you can request raw data form that authors.

yes I agree with Yohan Mahagamage , it depends on the region. Some countries, regions have good public data bases.

Yes you may find the same data from the government institutions or laboratories.

Hi Nega,

It would be good to check the land use in the area. Try to find some maps on the local changes in the land use. For example, diminishing forest covers may explain the increasing sedimentation of a lake. It would be good to check Government Agencies or NGOs which maybe monitoring the lake water quality.

If you are specifically studying nutrients, trace metals, POPs, it would be good to look at sediment cores which record these pollutants in the lake. Perhaps a signal of a specific metal from a certain industry can be detected. However, I suggest that you study this very carefully before proceeding. There are a lot of aspects that you should consider.

You have to check on the government or the local authorities in your area of interest who deals with water quality monitory for those data

By your local government development authorities Like Department of Statistics

Every country have some concern authorities assign to assess the quality of water regularly.