In recent years, as people's living standards improve, the hydrophilic environment has become a major demand, and maintain living quarters within the water or clean river water pollution is to improve the living environment, one important factor to attract buyers. However, since the residential area of ??water body is enclosed waters generally has water area is small, easy to pollution, water environmental capacity is small, and low self-purification capacity of water, if the water inside the residential area and river management is not good, the surrounding pollutants emissions are not strictly controlled, it is easy to become residents of the district sewage, rainwater and garbage the receptor, resulting in varying degrees of water pollution, seriously affecting the surrounding natural environment and the quality of the living environment. Cause more than a few reasons for the worsening water quality landscape in general can be divided into the following categories: 1, surface water sources around the landscape more often planted lawns, flowers and trees, the water often kept some of waterfowl, fish and shrimp like animals , for people to watch. As rainfall and irrigation water infiltration, will plant a variety of nitrogen, phosphorus, carbon, potassium and other nutrients and fertilizers, pesticides and leaves, hay and other "green waste" a large number of aggregated to the lowest-lying landscape water, these faces source pollution, making the further deterioration of water quality. In addition, the animal's metabolic substances will accelerate the growth of blue-green algae, the lake was anaerobic conditions, which in turn causes the fish died from lack of oxygen, decaying aquatic animals and their proteolytic make the water smell, in a vicious loop. 2, unreasonable design often seen in this area, because the design is not scientific, artificial lake often appear dead, and dead in the water due to lack of liquidity, are often the most likely to deteriorate. Various pollutants will be deposited in the corner office, and slowly contaminate the entire artificial lake, which makes the dead to become an artificial lake inside sources, therefore, an artificial lake, if dead, the more the faster deterioration of water quality. 3, the invasion of blue-green algae landscape water blue-green algae is public enemy number one. As blue-green algae spores can also be spread through the air, so they can settle in any place with water. This algal blooms fast, basically every 20 minutes to breeding a generation, and growth and reproduction of algae to consume large amounts of oxygen, this will affect a variety of aquatic plants and animals for normal growth, serious, can also cause aquatic plants and animals due to hypoxia and death.