Floods

Rivers That Reached New Highest Flood Level during Monsoon 2020

Flooding in Madhya Pradesh, late August 2020. Photo: MP Govt., flood list.

In 2020, south west monsoon season when rainfall was 8.74% above normal, rivers reached new Highest Flood Levels (HFLs) at least at 37 locations across the country, as per information available to SANDRP. Maximum 13 such instances come from Central and East India, each. Five instances happened in South India, three in North India and two in North East India. This article provides wise details and hydrographs of all these sites.

SANDRP has been tracking the Highest Flood Level (HFL) breach incidents during monsoon season. The analysis of such HFL breaches in 2018 and 2019 are available on our website. In 2018 we had listed 25 such instances though SW Monsoon rainfall was 9.4% below normal. In 2019 we listed 37 such instances when the SW Monsoon rainfall was 10% above normal.

North India

In North India, 3 Level Monitoring sites in Uttar Pradesh have breached the HFL. The New Motipur site crossed the HFL by 0.04 metre on July 9, 2020 and it was above HFL for about 12 hours. On July 10, 2020, the river again crossed the HFL. The Thoothibari site breached the HFL by 0.8 metre and it remained above (the old) HFL for about 20 hours. River Burhi Rapti has also crossed HFL at Parsohan Ghat however the old and new HFL are not available.

SNSiteRiverDistrictStateOld HFL (m)DateNew HFL (m)Date
1New MotipurSuhaliKheriUttar Pradesh134.220-09-2019134.2409-07-2020
2ThoothibariChandanMahrajganjUttar Pradesh100.1525-07-2019[i]100.9529-06-2020
3Parsohan GhatBurhi RaptiSiddharath NagarUttar PradeshNA26-06-2019NA12-07-2020

North East India

In North East India 2 rivers Dikhow at Sivasagar and Suklai at Suklai site breached the HFL. Both sites are in Assam state. The Sivasagar is Level Forecasting site and the Suklai is Level Monitoring site. The Dikhow at Sivasagar site breached the HFL marginally by 0.01 metre. The level remained slightly above or at old HFL for about 14 hours.

The Suklai breached the previous HFL of 75.23 metre by 0.12 metre setting new HFL of 75.85 metre. Only 10 of 118 sites on CWC FF list in the Assam have HFL dates in June month. Interestingly, the Suklai river touched the HFL twice first on June 27 at 10:00 hours after breaching it on June 26.

Also at Neamatighat Level Forecasting site in Jorhat district the river Brahmaputra fell short of HFL of 87.37 m (attained on July 11, 1991) by 0.02 m. On July 13, 2020, the river reached 66.56 metre at Tezpur Level Forecasting site in Sonitpur district which is 0.03 metre short of HFL 66.59 metre dated August 27, 1988.

SNSiteRiverDistrictStateOld HFL (m)DateNew HFL (m)Date
1SivasagarDikhowSibsagarAssam94.2301-08-201894.2422-06-2020
2SuklaiSuklaiKamrupAssam75.7325-09-201875.8526-06-2020

East India

In East India 14 sites have breached the old HFL of which 9 sites are in Bihar, 4 in Odisha and 1 West Bengal. In Bihar River Gandak, at Dumariaghat Level Forecasting site crossed the HFL by 0.35 metre and it remained above the old HFL level for about 50 hours. Gandak river also breached HFL at Rewaghat Level Forecasting site by 0.05 metre and it remained above old HFL for about six hours. The Lalganj Level Forecasting site on Gandak was also breached by 0.12 metre and the river stayed over old HFL for about 18 hours. This site was again breached in late Septermber.

At Belsand Level Monitoring site, the Bagmati river breached the HFL by 0.08 metre and it remained above the HFL for about 24 hours. The old HFL date is not available. The Moujabadi Level Monitoring site on Mahananda was also breached by 0.27 metre with river flowing over HFL for about 32 hours.

At Rosera Level Forecasting site river Burhi Gandak crossed the old HFL by 0.21 metre and the river was forecasted to stay over old HFL for about 30 hours. The Burhi Gandak river at Sakra Level Forecasting site crossed the old HFL by 0.53 metre and remained above the HFL for more than 130 hours. Bagmati river at Bishunpur (CWC earlier listed this on Adhwara River) first crossed the HFL on July 23, 2020 and remained above HFL for about 15 days.  

In Odisha, the river Bheden crossed the old HFL at Mahulpali Level Monitoring twice, first on June 21, 2020 and second time on August 27, 2020. The new HFL attained is 2.03 metre higher than old one. During second breach the river remained above HFL for about 15 hours. The Padampur Level Monitoring site on Ong river was also breached by 0.5 metre where Ong river flew over old HFL for about 18 hours.

The Subernarekha river also breached old HFL at Mathani Level Forecasting site by 0.25 metre and the river was above the old HFL for about 48 hours. Then the River Mahanadi breached the old HFL at Kanas Level Monitoring site by 0.01 metre remaining above the old HFL for about 10 hours. At Deogaon Level Monitoring site the river Mahanadi level increased to 130.12 metre on August 30, 2020 which is 0.04 metre less than of the old HFL 130.16 metre.

In West Bengal river Kaljani breached the old HFL by 0.3 metre at Ambari Level Monitoring site.

SNSiteRiverDistrictStateOld HFL (m)DateNew HFL (m)Date
1DumariaghatGandakGopalganjBihar64.117-08-201764.3624-07-2020
2RewaghatGandakMuzzafarpurBihar55.4117-09-198655.4624-07-2020
3LalganjGandakVaishaliBihar51.62404-08-200151.7525-07-2020
4Belsand[ii]BagmatiSheoharBihar58.10NA58.1812-07-2020
5Moujabadi[iii]MahanandaKishanganjBihar53.2814-07-201953.5528-06-2020
6SakraBurhi GandakMuzzafarpurBihar50.8728-08-201751.4028-07-2020
7RoseraBurhi GandakSamastipurBihar46.3516-08-198746.5631-07-2020
8DhamaraghatKosiKhagariaBiharNANANA12-07-2020
9BishunpurBagmatiDarbhangaBihar48.0424-08-201748.9705-08-2020
10MahulpaliBhedenSambalpurOdisha251.1506-07-2007252.6 253.1821-06-2020 27-08-2020
11PadampurOngRayagadaOdisha178.7427-08-2018179.2428-09-2020
12MathaniSubernarekhaBaleshwarOdisha6.8NA7.0527-08-2020
13KanasMahandiPuriOdisha5.4707-08-20145.4829-08-2020
14AmbariKaljaniCoochbeharWest Bengal40.512-08-201740.802-07-2020

Central India

In Central India 13 rivers have breached the previous HFL of which 7 sites are in Madhya Pradesh, 2 in Maharashtra and 4 in Chhattisgarh. The Wainganga at Keolari Level Monitoring site crossed the Old HFL by 2.23 metre. The river water level was above the old HFL for about 22 hours. At Gadarwara Level Monitoring site, the Shakkar river (Narmada Basin)    breached the old HFL by 2.36 metre. Here too, the water level was above the old HFL for about 22 hours. 

The Wainganga also breached the old HFL at Balaghat Level Monitoring site by 0.15 metre staying over the old HFL for about 15 hours. River Narmada crossed the old HFL at Handia Level Monitoring site by 0.44 metre where the level appeared to be above HFL for about 16 hours. In Chambal basin, the Parwati river at Astha Level Monitoring site crossed the old HFL twice both in August 2020. The breach was 2.08 metre higher on August 22, 2020 when the water level was above HFL for 28 hours. During second breach the level peaked to 100.95 metre and the water level remained above HFL for about 44 hours.

At Palwa Level Monitoring site the CHAMLA river whose name in not mentioned by CWC crossed the old HFL by 1.84 metre and the level remained above old HFL for 60 hours. Kalisindh river which is also part of Ganga basin crossed the old HFL at Sonkatch Level Monitoring site by 1.14 metre. The water level stayed over old HFL for about 10 hours.

In Maharashtra, the Kanhan river at Satrapur Level Monitoring site breached the old HFL by 0.82 metre and it the level remained above old HFL for about 14 hours. The Wainganga river crossed the old HFL at Sakhara Level Monitoring site by 5.625 metre. Available hydrograph shows the river was above HFL for more than 100 hours.

Image source CWC

In Chhattisgarh River Kharun at Pathardihi Level Monitoring site crossed the old HFL by 2.47 metre and the water level remained over old HFL for about 46 hours. The Kurubhata Level Monitoring site on Mand river was also breached by 0.05 metre for about 8 hours.

River Mahanadi at Kalma Level Monitoring site crossed the old HFL by 1.39 metre and the water level was above the old HFL for about 110 hours. The Mahanadi also breached the Surajgarh Level Monitoring site by 1.16 metre where the water level remained old HFL for about 100 hours.

SNSiteRiverDistrictStateOld HFL (m)DateNew HFL (m)Date
1KeolariWaingangaSeoniMadhya Pradesh440.821-07-1994443.0329-08-2020
2GadarwaraShakkarJabalpurMadhya Pradesh330.2615-07-1999332.6229-08-2020
3BalaghatWaingangaBalaghatMadhya Pradesh297.322-07-1994297.4530-08-2020
4HandiaNarmadaHardaMadhya Pradesh274.4622-08-2013274.930-08-2020
5AsthaParwatiSehoreMadhya Pradesh100.3208-09-2019102.4 100.9522-08-2020 30.08.2020
6PalwaCHAMLAUjjainMadhya Pradesh101.0909-08-2019102.9323-08-2020
7SonkatchKalisindhDewasMadhya Pradesh96.8308-09-201997.9722-08-2020
8SatrapurKanhanNagpurMaharashtra277.6106-09-1994278.4330-08-2020
9SakharaWaingangaGadchiroliMaharashtra93.13510-09-201998.7630-08-2020
10PathardihiKharunRaipurChhattisgarh279.2112-07-1994281.6829-08-2020
11KurubhataMandRaigarhChhattisgarh220.3510-08-2004220.428-08-2020
12KalmaMahanadiJanjgir-ChampaChhattisgarh201.0408-08-2018202.4329-08-2020
13SurajgarhMahanadiRaigarhChhattisgarh199.930-08-2003201.0629-08-2020

South India

In South India, old HFL has been breached at five locations this monsoon of which 3 sites are in Karnataka and 2 in Andhra Pradesh. In Karnataka the Cauvery river crossed the old HFL at Napoklu Level Monitoring site by 0.385 metre and the flood level remained over HFL for about 42 hours. The Bhadra river (Krishna basin) breached the old HFL at Lakkavalli Level Monitoring site by 2.79 metre where the water level remained above old HFL for about 46 hours. The west flowing Swarna river also crossed the old HFL at Yennehole in Udupi district  by 0.935 metre. The river water level stayed over old HFL for about 20 hours.

The CWC has changed the HFL for Chinturu and Atreyapuram Level Forecasting sites however the information sourced from CWC’s[iv] previous website shows that the new HFL are respectively 0.38 metre and 3.45 metre lower than the old ones.

SNSiteRiverDistrictStateOld HFL (m)DateNew HFL (m)Date
1NapokluCauveryKodaguKarnataka875.79528-08-2017876.1808-08-2020
2LakkavalliKrishnaChikmagalurKarnataka610.0805-09-2019612.8721-09-2020
3YenneholeSwarnaUdupiKarnataka25.11503-08-198226.0520-09-2020
4ChinturuSabriE GodavariAndhra Pradesh45NA44.9118-08-2020
5AtreyapuramGowthamiE GodavariAndhra Pradesh17.822-08-201814.3518-08-2020

Summary

Region/ State202020192018
North East: Assam222
                    Tripura002
EAST: W Bengal100
            Bihar930
             UP310
             Odisha410
             Chhattisgarh400
SOUTH: AP200
               TN024
               Karnataka3154
               Kerala0513
WEST: MP710
             Rajasthan020
             Maharashtra250
Rainfall Departure+8.74%+10%-9.4%
No of HFL crossing instances373725

Note: The number of HFL crossing instances given here may not be exhaustive, since these are as per SANDRP records. CWC does not publish year end reports that include such lists.

SANDRP tweet thread on sites breaching HFL in monsoon season 2020.

Discussion HFL breach incidents are important indicators revealing crucial information about flood cycles of rivers and also about management of dams during the monsoon. In past reports, we have raised several issues and inconsistency in data given by Central Water Commission (CWC). On CWC-FF site, there is no archive of HFL breach events in public domain. Secondly CWC has not been regularly updating the HFL breach incidents on its website.

One new emerging issue noticed is that several new sites added by CWC generally lack HFL details but during monsoon season, these sites are shown breaching HFL. Later on the level in hydrograph is removed. One example of this is New Motipur site on Suhali river in Kheri district of Uttar Pradesh. On July 10, 2020, one CWC hydrograph showed the site crossing old HFL as 134.2 and setting new HFL of 134.24. However the very next day the HFL was removed[v].

When requested, CWC FF replied, “The site was established last year only. The peak which was attained last year when no major flood occurred was marked as Highest Flood Level. This gives a wrong picture when there is no flood in the area it was showing extreme flood. Hence HFL was removed for this station”

And this has happened with several new sites which were first shown breaching HFL but later on the HFL was removed.

Another issue observed this year is that CWC has been changing HFL of some sites without making corresponding changes to upstream and downstream sites.

This happened in the case of Ambari[vi] site on Kaljani river in Coochbehar district of West Bengal. The CWC, first on July 02, 2020, mentioned that the river was flowing in extreme flood situation at the site which was on the basis of changed HFL of 40.5 m on 12th August 2017. https://twitter.com/CWCOfficial_FF/status/1278633734250496003?s=20

When CWC was informed that old HFL for the site was 42.78 m dated 21-07-1993 and for downstream site Shaladang as 37.07m dated 21-07-1993 which was changed to 36.2 m. It was also highlighted that in comparison to Ambari, there was no corresponding changes in water level at Shaladang site and new HFL cannot be lower than the previous one.

CWC first replied that “Levels taken in 1993 was Arbitrary without any GTS Bench Mark connection. The GTS Bench Mark survey was conducted recently based on which the readings of HFL has changed for some stations. The levels have been updated based on the survey accordingly more reliable”. https://twitter.com/CWCOfficial_FF/status/1278654586790674432?s=20

But later on CWC clarified that “Now it has again been confirmed from the concerned Division, there is still some problem with the concerned Double Levelling Survey also and as there is no corresponding increase in downstream levels, they are again going for new survey until then they will continue with old HFL” https://twitter.com/CWCOfficial_FF/status/1278678517257957376?s=20

It further replied that “If any correction is required then it will be done after the re-survey only. Accordingly, they are changing the HFL to the old readings. This may take a day and tomorrow or day after they will change back to old HFL.” https://twitter.com/CWCOfficial_FF/status/1278679130888757248?s=20

This shows clear anomalies in CWC survey works and coordination with divisional officials. If we go by the new level the site has breached the HFL and if we revert back to old HFL, the site has not crossed the HFL. There have been several such incidents showing lack of consistency or transparency in the premiere agency.

The case of the Bishunpur site shown for long on Adhwara river in Darbhanga district of Bihar is most curious one. The location of the site was shown in Adhwara basin. The site has been above HFL for about 15 days. And later on CWC revealed that the site is in Bagmati basin. When we could not locate it on Adhwara river, we kept asking CWC for Latitude Longitude of the location, but shockingly, we were told CWC does not have latitude longitude of its flood forecasting sites!

There is possibility of sites particularly Level Monitoring sites and new sites breaching HFL, however these are not being monitored properly by CWC and CWC does not list their breaching HFL either on twitter or on its daily reports.

SANDRP (bhim.sandrp@gmail.com)

[i] The HFL date was shared by CWC on twitter and has been updated on website. https://twitter.com/CWCOfficial_FF/status/1277884242601455620?s=20

[ii] The new and old HFL levels are based on assumption of hydrograph. The actual ones could be different. The date of old HFL is not available.

[iii] The HFL date was shared by CWC on twitter and has not been updated on website.

[iv] https://sandrp.in/2019/10/18/south-india-overview-of-cwc-flood-forecasting-sites-2019/

[v] https://twitter.com/Indian_Rivers/status/1281824364825124864?s=20

[vi] https://twitter.com/CWCOfficial_FF/status/1278633734250496003?s=20

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