Thiruvananthapuram: The heavy rains that have battered Kerala since August 1 have claimed 25 lives, left four people missing, injured 10 and damaged hundreds of properties, forcing thousands to seek shelter in relief camps, the state government said on Tuesday.The government said 52 houses were destroyed and 565 homes were partially damaged between August 1 and August 4. More than 18,000 people have been shifted to over 400 relief camps across the state.The highest number of people moved to camps are in Pathanamthitta (7,852), Kottayam (5,288) and Alappuzha (2,651) districts, where several areas remain flooded.The state received nearly three times its normal rainfall during this period, according to official data.Kerala received 205.8 mm of rainfall between August 1 and 4, against the normal 73.2 mm, recording an excess of 181 per cent, the data showed.As heavy rains continued to lash parts of Kerala, the India Meteorological Department issued a 'red alert' for eight districts - Pathanamthitta, Kottayam, Idukki, Ernakulam, Kozhikode, Wayanad, Kannur and Kasaragod - on Tuesday.The IMD also issued an 'orange alert' in four districts - Alappuzha, Thrissur, Palakkad and Malappuram - and a 'yellow alert' in Thiruvananthapuram and Kollam districts.The weather agency issued an 'orange alert' in nine districts for Wednesday.A 'red alert' indicates extremely heavy rainfall of over 20 cm in 24 hours, while an 'orange alert' signifies very heavy rainfall between 11 cm and 20 cm, and a 'yellow alert' indicates heavy rainfall between 6 cm and 11 cm.Earlier, the IMD said northern districts received the highest rainfall during the 21 hours ending at 5.30 am on Tuesday.As rains continued, several low-lying and riverside areas of Alappuzha, Pathanamthitta, Kottayam and Kozhikode remained flooded, forcing people to shift to relief camps and resulting in the loss of valuable documents and children's school books.State Tourism Minister P C Vishnunadh said special adalats would be held for restoring documents lost in the floods and that the government would ensure students receive the required textbooks and other study materials.He said the government had sanctioned Rs 25,000 for cleaning work in every ward and that several volunteer organisations had come forward to help clean homes where floodwaters had entered.Chief Minister V D Satheesan has announced that financial assistance would be provided without delay to those who lost homes and livelihoods.Bayar in Kasaragod recorded the highest rainfall in the state at 121.5 mm between 3 am on August 3 and midnight, the IMD said.Muliyar, also in Kasaragod, received 81 mm, while Kannur Airport recorded 74 mm. Urumi in Kozhikode received 65 mm.Among other locations that recorded significant rainfall, Cheruvanchery in Kannur and RARS Pilicode in Kasaragod received 59.5 mm each, while Neryamangalam in Ernakulam recorded 59 mm.The IMD considers rainfall of 60 mm and above in 24 hours as heavy rainfall.According to the latest official update, water levels in the Muvattupuzha and Thodupuzha rivers remained above the warning level on Tuesday morning, though they were receding.At 8 am, the water level in the Muvattupuzha river stood at 11.60 metres, above the warning level of 10.92 metres and close to the danger mark of 11.93 metres. Officials said the level was falling.The Thodupuzha river recorded a water level of 11.50 metres at 8 am. The warning level for the river is 10.78 metres, while the danger mark is 11.79 metres.The Kaliyar river was flowing at 12.26 metres, below its warning level of 13.10 metres and danger level of 14.10 metres.The water levels in these rivers were reported to be receding.Authorities are continuing to monitor the rivers and have advised people living along the banks to remain alert as the monsoon continues to bring rain to several parts of the state.Additionally, water levels in several major power generation dams have reached the 'red alert' level. These include Moozhiyar in Pathanamthitta; Kallarkutty, Erattayar and Lower Periyar in Idukki; Poringalkuthu in Thrissur; and Kuttiyadi in Kozhikode.