RIVER SYSTEM AND WATER RESOURCES:-
Other Rivers:-Among the minor channels which traverse the district is river Tons(Tamasa), into which the Chhoti Saryu flows. This river takes its rise many kilometres beyond the borders of Azamgarh in the Faizabad district. It flows parallel with the Ghaghra till it caters the district 9.6 km. north-east of Mahul. It is soon after joined by a small tributary called the Majhoi on the borders of pargana Nizamabad and it flows then in a very tortuous course for about 56 km. to the station of Azamgarh. Then it runs north-eastwards for 12 km. to Birman in the south of Sagri and then south-eastwards past Muhammadabad to the point of junction with Chhoti Saryu. The stream of the Tons is perennial but during the dry months of the year only a sluggish current of water flows in the bottom of its bed.
LAKES:-Lakes and jhils of the district are not only very numerous, but in many cases of considerable size. The more important of them are, in the southern tract, those known as Kotail, Jamuawan, Gumadih, Kumbh, Pukh, Asaune and the largest of all the Gambhiran. In the northern section of the district , the only lakes that deserve mention are Koila, Kasila-Gasila, Kaili, Duhia Birna, Ara Telhnan and Manchhil. The Salona Tal in Sagari tehsil is estimated to be over 3660 metres long by about 2750 metres broad, its depth being some 6 metres. The Pakri-Pewa Tal in Ghosi tehsil is 9.6 km. long and 3.2 km. broad while the Narya Tal in Muhammadabad tahsil and the Ratoi Tal in Ghosi tahsil cover each some 2023 heactares.
The climate of the district is moist and relaxing except in winter and hot seasons. The year may be divided into four seasons. The period from March to the middle of June is the hot season. The south west mansoon season which follows continues up to about the end of September . The succeeding period lasting till end of November is the post mansoon or transition season. The period from December to February is the cold season.
RAINFALL:-The average annual rainfall in the district is 1021.3 mm. and it varies from 979.1 mm. at Deogaon to 1060.4 mm. at Azamgarh. On an average there are 50 rainy days(i.e. days with rainfall of 2.5 mm. or more) in a year in the district. This number varies from 48 at Deogaon to 52 at Azamgarh.For agriculture purpose the most critical period is rainy season from June to October. Agriculturists reckon during that season by the periods which are known as maha nakshatrs, and which they call nakhats. There are twenty-seven nakshatrs in the solar year. The six nakhat to the period between June 19th and the 2nd July is known as adra. The 13th is known as hast or hathia and corresponds to the period between September 24 and 7th October. A favourable season for agriculture begins with a good fall in rain early in adra and ends with a similar fall in hast. The popular saying is:-
Charhat barse Adra, utrat barse Hast,