"So, there is a real mixed picture - New Zealand has got some of the clearest and best-quality water in the world, but we also know that there are areas that are very much under pressure."
LAWA's lake science lead Dr Jane Groom said the freshwater monitoring showed the difference between high and low-lying lakes.
"In our analysis we found 82 per cent of monitored lowland lakes are in a 'poor' or 'very poor' condition, meaning they are nutrient-enriched with an increased likelihood of algae bloom events," Groom said in a statement.
It is hoped that people will use the interactive map to find information about the state of lake health by looking at information about the history of their "nutrients, algae, bacteria, and water clarity", she said.
Water quality in rivers and streams is likely to be worse in areas that have been highly modified, whether because of urban environments or pasture, the scientists say.
LAWA's river science lead Dr Coral Grant said the data shows that two-thirds of river sites monitored for E. Coli were graded D or E, which meant that the predicted likelihood infection for anyone who had contact with that water was 3 per cent on any given day.
"There is no evidence of positive change in the proportion of sites graded poorly for E. coli at a national level, but there are individual sites that show signs of improvement, so change is possible," Grant said in a statement.
