1. The Markanda & its tributaries 

2. The Dangri (Tangri) & its tributaries 

3. The Ghagghar & its tributaries 

The Markanda and  the Dangri streams ultimately drain into the Ghagghar river beyond the territory of the district. The Ghagghar along with its tributaries however constitutes an inland drainage system. 

The Markanda

The Markanda which drains the southern slopes of Dharti Dhar range (Himachal Pradesh) , cuts through the shivalik range and enters the plains and the district. The river channel which is broad between Kala Amb and Mullana becomes narrow to the south of Mullana. During the rainy season, the river carries enormous water which causes flooding in its lower course.  

The Dangri

The Tangri streams rises in the Morni Hills and flows in a southerly direction upto village Chajju Majra where it is joined by the Baliali Nadi. It further flows a southerly course running on the eastern side of Ambala Cantonment. After crossing the Ambala Cantonment Ambala-Jagadhari railway line it takes south-westerly direction . Near the villages of Segta & Segti the torrent of Omla and Amri join the Dangri. It is here that the Narwana branch of Bhakhra main canal crosses the Dangri stream. Thereafter the Dangri takes a westerly course upto village Niharsi where it turns towards south and leaves the district to enter the Patiala district of Punjab. 

 The Dangri rising from Morni Hills , used to flow on a southerly direction upto Panjokhra, a village in the North-East of Ambala from where it was separated into two main channels. These two channels still kept a southerly course running on either side of Ambala cantonment. The Dangri seems to have changed its course towards the close of 19th century when the drainage was confined to the eastern channel.The Baliali Nadi rises in the southern slopes of the Morni Hills and joins the Dangri stream near village Chajju Majra. The Amri ( also known as Shahzadpur wali or Dadri) is formed of water collected in plains during the rainy season. It starts near Rataur and flows south-west and takes the torrent of the Omla and joins the Dangri between the villages of Segta and Segti.  

The Ghaggar   

The Ghagghar, another important river also traverses the district for some distance in the north west. The river originates in Sirmaur district of Himachal Pradesh and enters the district. It  traverses the district near Ambala City for a very short distance and then flows parallel to the  district boundary outside the district .While in its-upper course , the river contains some water throughout the year, in its lower course it is generally dry in summer and carries water only during the rainy season.The two tiny lakes at an elevation of 620 metre above mean sea level near village Masiyun in the Morni hill tract are of little importance as these lakes neither feed any major stream nor are these being fed by any major river. Only a small stream from one of these lakes joins the Dangri (Tangri) nadi. Despite the large number of drainage lines passing through the district, the area suffers from inadequate water resources. Canal irrigation, which is limited to a few small pockets in the south-western tip of Ambala tehsil, does not have much scope for extension because of undulating topography in a large part of the district. Thus, wells and tubewells remain the major source of irrigation in the district.