Floods & Flood Monitoring in Yamuna: July 2018

The release of around 1.31 lakh cusecs of water in Yamuna from Hathnikund barrage at 09:00 hours on July 26, 2018, was certainly first surge of flood this monsoon in the river. But no one expected, most are still in the dark that the release would multiply by over five times in just two days! It is almost a month after the Southwest monsoon arrived. By this time the river usually floods couples of times.

Looking at the lack of significant rainfall in the catchment area over past weeks, the flood is unexpected and has taken many by surprise. The Irrigation and Flood Control Department, Delhi Government has issued warning for flood plain farmers and human settlements close to river banks, but the warning does not seem to commensurate with the flood peak that is likely to hit the capital in next day or two.

Yamuna has already crossed warning (204 m) and danger level (204.83) at Old Delhi Railway Bridge (ORB), Delhi. The High Flood Level is 207.49 meters, reached on Sept 6,1978 after around 7 lakh cusecs (cubic feet per second) water was released in Yamuna on 3^rd Sept 1978 at 04:00 hrs from Tajewala barrage, that was decommissioned and replaced by Hathnikund barrage in early 1990s. The flood monitoring of River Yamuna began in 1963.

Since then, the river has seen high floods in 1988, 1995, 2010 and 2013. The 2010 and 2013 floods also crossed 207 metres mark but fell short of 1978 level.

However, for the last three days, there has been significant rain in the Yamuna catchment in Himachal, Uttrakhand, Haryana and Uttar Pradesh. The river has started swelling and what first was believed to be a mild flood spell is turning out to be big flood event.

The discharge of about 2 lakh cusecs flood can cause a low level flood in Delhi. Discharges between 3 to 5 lakh cusecs can result in medium scale flood in the capital. And the discharge beyond 5 lakh cusec from Hathnikund can bring a big flood in Delhi submerging floodplains and threatening the embankments.

Usually the first flood spell reaches Delhi in about 72 hours. Once river bed and adjoining area are saturated by rain and river discharges, the flood water takes about 60 hours to reach the threshold of Delhi.  As per CWC forecast, the discharges mentioned in the table below will be taking about 62 hour’s time to reach Delhi.  

Discharge from Hathini Kund Barrage on 28 July 2018

SN	Time	Discharge ( In lakh cusecs)
1	0700 hrs	1,80,000
2	0800 hrs	1,93,607
3	0900 hrs	2,11,874
4	1000 hrs	2,55,137
5	1100 hrs	3,11,190
6	1200 hrs	3,56,717
7	1300 hrs	4,24,763
8	1400 hrs	4,80,557
9	1500 hrs	5,03,925
10	1600 hrs	5,03,925
11	1700 hrs	5,27,362
12	1800 hrs	6,05,949
13	1900 hrs	5,63,186
14	2000 hrs	5,63,186

Flood situation at different locations along Yamuna:

Badkot, Uttarkashi The river has reportedly engulfed several adjoining farmlands at Tiladi ghat. An electric poll has been washed away at Kharadi and retaining wall of an under construction bridge has also been damaged at Than village. The bridge, incidentally was washed away in 2010 floods and has not been rebuilt since then.

 

Yamuna River water level at Mungra Bridge Naugaon, 28 July 2018 (Map source; CWC & Image by Tilak Ramola) 

At Naugaon, the river has touched 1059.60 metres mark on 28 July 2018 around 12 hours at Centre Water Commission (CWC) level monitoring site located downstream of Mungra bridge. The highest flood level was marked 1060.40 at this location in 2010. So this seems to be a huge flood after 2010. The water level has stabilised and started showing downward trend but ongoing rain could swell the river dangerously.

Katapathar, Vikas Nagar, Dehradun The river channel is full. At 15 hours on 28 July 2018 it was reported to be rising further. Local people say that the river reminds them of 2010 flood when a long patch of Khair forest on a river island was swept away like dry twigs.

Video showing flooded Yamuna river at Vyasi Hydro Power Project, Juddo, Dehrudun (Video by Parveen Tomar, Katapathar, 28 July 2018) 

The floods then had also damaged the Bausan flood monitoring site. It was later buried under the debris of Vyasi Hydro Power Construction. The CWC seems to have not rebuilt the flood monitoring site. The normal life has been affected and people are staying indoors fearing landslide or other flood disaster. The Ponta level monitoring site is rising constantly and has touched 382.500 metres mark at 17 hours on 28 July 2018.

Kanalsi – Yamuna Nagar 1.81 lakh cusecs water was released in River Yamuna on 26 July 2018 at 19:00 hours. Since then on an average 1 lakh cusec plus water is flowing in the river. As per villagers the river started eroding banks downstream Kanalsi village in Yamuna Nagar, Haryana. The villages located close to river banks have been alerted about rising water level.

The rain has stopped there, but given the water level and discharge rise at Poanta and Hathini Kund Barrage, Yamuna Nagar, there would be more and bigger discharges in the river which may cause bank erosion and threat to embankments in Karnal and Paipat. The water level is rising at Kalanaur (UP), Karnal (Haryana) and Mawi (UP) level forecasting site.

(Hydrographs for Kalanaur and Mawi sites show rising trend on 28 July 2018) 

Delhi The flood level in Delhi is on constant rise. There are three flood monitoring site in Delhi which are Palla, Jhangola and Old Railway bridge. The river has already crossed warning and danger level.

The present water level at Palla is at 210.3 metres. It is rising up and will cross the warning level of 210.6 metres and may touch the danger level of 211.8 metres. Flood water has started spreading in floodplains. The floodplain farmers have been put on alert. If it rains more, Delhi may well see a bigger flood spell.

About CWC Flood forecasting and level monitoring sites.

List flood forecasting and level monitoring sites in Yamuna Basin

List Flood Forecasting Sites

SN	River	Site	District/ State	WL	DL	HFL (M)	HFL Date
1	Yamuna	Paonta	Sirmaur, HP	383.5 M	384.5 M	384.6 M	05-09-1995
2	Yamuna	Karnal	Karnal, Haryana	248.8 M	249.5 M	250.07 M	17-06-2013
3	Yamuna	Mawi	Muzzafar Nagar, UP	230.0 M	230.85 M	232.75 M	18-06-2013
4	Sahibi	Dhansa	South West, Delhi	211.44 M	212.44 M	213.58 M	06-08-1977
5	Yamuna	Delhi Railway Bridge	North, Delhi	204.0 M	204.83 M	207.49 M	06-09-1978
6	Yamuna	Mathura (Prayag Ghat)	Mathura	165.2 M	166.0 M	169.73 M	08-09-1978
7	Yamuna	Agra (J.B.)	Agra, UP	151.4 M	152.4 M	154.76 M	09-09-1978
8	Betwa	MOHANA	Jalaun, UP	121.66 M	122.66 M	133.35 M	11-09-1983
9	Yamuna	Etawah	Etawah, UP	120.92 M	121.92 M	126.13 M	11-09-1978
10	Yamuna	Auraiya	Auraiya, UP	112.0 M	113.0 M	118.19 M	25-08-1996
11	Yamuna	KALPI	Jalaun, UP	107.0 M	108.0 M	112.98 M	25-08-1996
12	Yamuna	SHAHIJINA	Hamirpur, UP	103.54 M	104.54 M	108.67 M	NA
13	Ken	BANDA	Banda, UP	103.0 M	104.0 M	113.29 M	07-07-2005
14	Yamuna	HAMIRPUR	Hamirpur, UP	102.63 M	103.63 M	108.59 M	12-09-1983
15	Yamuna	CHILLAGHAT	Banda, UP	99.0 M	100.0 M	105.16 M	06-09-1978
16	Yamuna	NAINI	Allahabad, UP	83.74 M	84.73 M	87.99 M	08-09-1978

 List of Level Monitoring Sites

SN	River	Site	District	State	HFL (M)	HFL Date
1	Yamuna	Hanuman Chetty	Chamba	Himachal Pradesh*	NA	NA
2	Yamuna	Naugaon	Uttarkashi	Uttrakhand	1060.4 m	11-09-2010
3	Pabar	Tuini (Pabar)	Dehradun	Uttrakhand	931.88 M	25-09-1988
4	Tons	Tuini (Tons)	Dehradun	Uttrakhand	904.0 M	24-09-1988
5	Tons South	Haripur	Dehradun	Uttrakhand	482.48 M	25-09-1988
6	Yamuna	Kalanaur	Saharanpur	UP	268.66 M	08-09-2010
7	Yamuna	Masani	Rewari	Haryana	242.58 M	NA
8	Hindon	Galeta	Baghpat	UP	217.72 M	04-09-1978
9	Yamuna	Baghpat	Baghpat	UP	217.18 M	27-08-1988
10	Sahibi	Dadri	Jhajjar	Haryana	214.98 M	26-08-2008
11	Yamuna	Palla	North West	Delhi	213.275	1988
12	Betwa	NAUTGHAT	Jhansi	UP	207.99 M	01-09-1983
13	Yamuna	Mohna	Faridabad	Haryana	193.13 M	06-09-1978
14	Yamuna	Mathura (Gokul Barrage)	Mathura	UP	166.17	26-09-2010
15	Chambal	UDI	Etawah	UP	128.4 M	24-08-1996
16	Yamuna	RAJAPUR	Chitrakoot	UP	96.37 M	07-09-1978
17	Yamuna	PRATAPPUR	Allahabad	UP	90.1 M	08-09-1978
18	Betwa	Matatila	Lalitpur	UP	NA	NA

List of Inflow Monitoring sites

SN	River	Sites	District	State	FRL	MWL
1	Yamuna	Hathinikund Barrage	Yamuna Nagar,	Haryana	NA	NA
2	Yamuna	Tajewala Weir (Hathinikund)	Yamuna Nagar,	Haryana	NA	NA

Overall there are 36 flood forecasting, level monitoring and inflow monitoring stations comprising of 16 Flood forecasting, 18 Level monitoring and 2 Inflow monitoring station on River Yamuna and its tributaries in Uttrakhand, Himachal Pradesh, Haryana, Delhi and Uttar Pradesh states.

Serious lacunae in CWC flood forecasting in Yamuna basin As we see, there are several problems with the CWC flood monitoring system[i]. A few are mentioned here.

1. The Hanuman Chuttey site is in Uttarkashi, Uttrakhand but CWC website shows this in Himachal Pradesh. It is the first level monitoring site on River Yamuna close to its origin downstream the confluence of Hanuman Ganga. But the site is inactive, hence there is no information about river water levels from this site.
2. The Bausan site at Katapathar, Dehradun has been damaged in 2010 and currently is non-functional and buried under the debris of Vyasi Hydro Power Project. Hence there is no forecasting or monitoring station when river Yamuna enters the plains from mountain area.
3. The sites shown with red colour are lying inactive. These sites should have been active or removed from CWC flood forecasting list.
4. The sites in the table with green colour has no information about high flood levels and date but the hydrograph for these site is active. CWC should provide complete information about these site.
5. Similarly the Full Reservoir levels and Maximum Water Level is not mentioned for the two inflow monitoring sites.
6. The Tajewala Weir is completely destroyed by 2010 floods but it is still shown on the website, though without any information. The location of the site is also wrongly shown far away from its location on Yamuna river, in Yamuna Nagar to South Haryana, along Sahibi river.

The coming floods will further test the Delhi govt, CWC and the disaster management systems and of course the people all along Yamuna as the flood travels further downstream of Delhi.

Bhim Singh Rawat, SANDRP (bhim.sandrp@gmail.com)

END NOTES: 

[i] http://www.india-water.gov.in/ffs/current-flood-forecast/

Post Script:-

As latest CWC hydrograph Yamuna river level has reached 205.50 metres and about 1500 people have been evacuated from floodplains in Delhi.  https://www.news18.com/news/india/as-yamuna-flows-above-danger-mark-1500-delhiites-evacuated-from-low-lying-areas-1826995.html ( 29 July 2018)