README
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This readme file was generated on 2025-10-XX by Joel Segersten and provides a list and description of the files included in the dataset.

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DATASET GENERAL INFORMATION
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Dataset title, ENG: Swedish_Bypassed_River_Reaches_Register_SBRRR

Dataset title, SWE: Torrfåreregistret

DOI: https://doi.org/10.5878/fgz3-v727.

Creators: Joel Segersten, Roland Jansson, Erik Degerman, Serena Donadi, Åsa Widén, Birgitta Malm-Renöfält, Brendan G. McKie

Responsible organization: Swedish University of Agricultural Sciences

Additional information: See the Researchdata.se catalogue entry for this dataset for complete metadata, including the dataset description, recommended citation, contact information, and information about how to obtain the dataset.

Description: The_Swedish_Bypassed_River_Reaches_Register_SBRRR is a dataset containing descriptive information about 968 unique bypassed river reaches located at Swedish diversion hydropower stations. These are formerly natural river reaches currently more or less devoid of water due to hydropower operations. The dataset contains information about the intrinsic hydrogeographical characteristics (i.e. prior to hydropower development) of these reaches such as channel slope, altitude, natural flow regime, catchment geology and soil characteristics, etc. The dataset also contains information about the size of the bypassed reaches (length, area), current management practices in terms of allocation of water as minimum discharge and any other implemented restoration measures (e.g. fishways, habitat enhancement) and additional pressures on the aquatic ecosystem of the bypassed reach (i.e. anthropogenic land use in the catchment area).

License: Creative Commons Public Domain Dedication (CC0 1.0)) 

Access restrictions: None

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DATASET ORGANISATION
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The dataset consists of the following files:
(1) Swedish_Bypassed_River_Reaches_Register_SBRRR.xlsx
(2) README_SBRRR.txt

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DATASET ORGANISATION
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(1) Swedish_Bypassed_River_Reaches_Register_SBRRR.xlsx (57 columns, 968 rows)
- Descriptors of bypassed reaches at Swedish diversion hydropower stations.
- Some columns in the table contains text information, others hold numerical data (details below).
- Missing values are indicated by empty cells in the table. 


Columns:
BR_ID						Identifier for the bypassed reach
River_name1					Name of river where BR (Bypassed reach) is located [text]
River_name2					Alternative name of river where BR is located [text]
NAMN_KRV_1					Name of the hydropower station where BR is located [text]
NAMN_KRV_2					Alternative name of the hydropower station where BR is located [text]
Stream_order				Bottom up (or Horton) stream order, i.e. 1 at river mouth, increasing as river branches moving upstream [factor, 5 levels: "1", "2", "3", "4", "5"]  
MQ							Modelled (S-HYPE 2019) natural mean annual discharge. Mean over a period of years (1981-2010). Natural indicates that the model assumes that there is no anthropogenic diversion or storage of water (e.g. from hydropower) upstream in the catchment. Rather, the model gives the (hypothetic) natural discharge under pristine unimpacted conditions [numeric; unit: m3/s]
Mean_area_specific_discharge
							Calculated from MQ and catchment area [numeric; unit: l/(s*km2)]
MLQ			 				Modelled (S-HYPE 2019) mean annual low flow. Annual minimum discharge (mean of a day). Mean over a period of years (1981-2010). MLQ sometimes used as an estimate of the base flow of a Swedish river [numeric; unit: m3/s]
MHQ							Modelled (S-HYPE 2019) annual maximum discharge (mean of a day). Mean over a period of years (1981-2010) [numeric; unit: m3/s]
MHQdivMQ					MHQ divided by MQ. Relative mean annual low flow, or approximate relative base flow at the reach [numeric; fraction]
MLQdivMQ					MLQ divided by MQ. Relative mean annual high flow [numeric; fraction]
Large_river					Large rivers are those with a MQ ≥ 20 m3/s, as defined by Swedish EPA (2020) [factor, 2 levels: Y=yes or N=no]
Catchment_area				Catchment area of BR [numeric; unit: [km2]
Relative_BR_Catchment_area	A measure of river network centrality. The ratio of the catchment area of the BR and catchment area at the river mouth at the sea [numeric; fraction; unit: %]
Anthropogenic_land_use		Proportion of anthropogenic land use in catchment: Agricultural land + urban area + other hard surfaces (e.g. roads, roofs) [numeric; fraction; unit: %]
Proterozoic_bedrock			Proportion of Proterozoic bedrock in the catchment area [numeric; fraction]
Caledonian_bedrock			Proportion of Caledonan bedrock in the catchment area. Caledonian bedrock is from the most recent orogeny in Scandinavia, forming the Scandinavian mountain range [numeric; fraction]
Platformal_sedimentary_cover_rocks
							Proportion of Platformal sedimentary cover rocks in the catchment area [numeric; fraction]
Mud_morain_and_or_silt_soil	Proportion of Mud-morain and/or -silt soil in the catchment area [numeric; fraction]
Peat_soil					Proportion of peat soil in the catchment area. Two soil types with high content of mud and/or silt. Deposits of mud-moraine of glacial origin, deposits of mud-silt of postglacial origin [numeric; fraction]
Elevation					Average of elevation of endpoint of BR and startpoint of BR [numeric; unit: masl]
Reach_type					Result from grouping of BRs into reach types based of intrinsic hydrogeographical characteristics [factor, 7 levels: 1=Southern platformal group, 2 =Southern coastal group, 3=Southern steeply sloped group, 4=Southern inland group, 5=Northern inland group, 6=Northern large rivers group, 7=Northern alpine group]
BR_Lenght		 			Lenght of BR [numeric; unit: km]
Elevation_difference_BR		Elevation difference between endpoint and startpoint of BR [numeric; unit: m]
Slope						Slope of BR [numeric; unit: %]
Slope_and_river_size_indicates_riffle_or_rapid_dominance
							Slope needed for ≥ 50% prob. of riffles, rapids or waterfalls = 3.791 * catchment area (km2)-0.408 (an area specific discharge of 8-12 l/s*km2 is assumed, additional details in Widén et al., 2022b) [factors, 2 levels: Y=yes or N=no]. 
Lenght_riffle				Lenght of BRs with riffle/rapid habitat dominance [numeric; unit: km]
Diversion_dam_height		Height of the diversion dam at the upper end of the BR [numeric; unit: m]
Total_head					Sum of elevation difference BR and Diversion dam height [numeric; unit: m]
BR_width					Width of the BR. Calcuated as: Log [Width (m)] = 0.487 * Log [Catchment area (km2)] + 0.016*Runoff (l/s*km2) - 0.203. Further details in Supporting information S2 [numeric; unit: m]
BR_area						Area of the BR. Calculated as lenght * width [numeric; unit: km]
Verified_info_on_MMD		MMD= mandated minimum discharge in the BR. We consulted with representatives from county administrative boards, water authorities, water regulation companies and/or relevant energy companies, and asked for information on weather the BR had a mandated minimum discharge or not. This column reflects the response frequency [factor, 2 levels: 1=yes or 0=no]
MMD							This column reflects the frequency of BRs with a MMD [factor, 3 levels: yes=the BR has a MMD, no= the BR has no MMD, NA=no verified information on weather the BR has a MMD or not]
MMDw						The weighed mean annual MMD. In some BRs the MMD was higher some times of the year (MMDMax) and lower at other times (MMDMin). MMDw was calculated as: MMDw= (MMDMax*dMax+ MMDMin*dMin) /365 where dMax and dMin are number of discharge days with MMDMax or MMDMin respectively. If number of discharge days with MMDMax had not been supplied to us we assumed a 50/50 MMDMax/MMDMin proportion [numeric; unit: m3/s]
MMDw_proportion_MQ			The proportion MMDw is of MQ [numeric; unit: %]
MMDMin_equal_to_0_m3_s		BR with a MMD where MMDMin was 0 m3/s during periods of the year [factor, 2 levels: 1=yes or 0=no]
MMDMin_larger_than_2_m3_s	BR with a MMD where MMDMin is higher than 2 m3/s [factor, 2 levels: 1=yes or 0=no]
MMDMin_larger_than_MLQ		BR with a MMD where MMDMin is higher MLQ [factor, 2 levels: 1=yes or 0=no]
MMDMin						In some BRs the MMD was higher some times of the year (MMDMax) and lower at other times (MMDMin) [numeric; unit: m3/s]
MMDMax						In some BRs the MMD was higher some times of the year (MMDMax) and lower at other times (MMDMin) [numeric; unit: m3/s]
Other_water					Yes indicates that the BR, while not having a MMD, had an identified input of water from tributaries, and/or from structural aspects of the hydropower facility. Only cases where it was evident that water always flowed into the BR (e.g. weir-like diversion dam, obvious spillover from intake channel, etc.) was classified as having other water due to structural characteristics of diversion dam [factor, 2 levels: 1=yes or 0=no]
Length_other_water_div2		Lenght of the BR with other water diveded by 2.  Based on the conservative assumption that if a tributary empties into the BR, on average, this happens at the midpoint of the BR [numeric; unit: km]
Quantitative_data_on_inflow_from_tributaries
							Indicates weather inflow of other water from tributaries has been quantified or not [factor, 2 levels: 1=yes or 0=no]
Inflow_from_tributaries		Sub-catchment area weighed modelled (S-HYPE 2019) MQ of tributaries emptying into the BR [numeric; unit: m3/s]
Water_avaliability_category	Water avalability categories [factor, 3 levels:  MMD=the BR has water from MMD, Other water=the BR has no MMD, but inflow of other water, No water=the BR has no identified input of water from MMD, tributaries or structural characteristics of the hydropower facility]
Number_of_different_restoration_measures
							Number of types of restoration measures in the BR, reported as finished or initiated in 2010 or earlier. Included measures where those In the categories “hydrological restoration”, ”biotope enhancement” (i.e . addition of gravel, large boulders or woody habitat elements) or ”fishway” (i.e. the construction, improvement or repair of a fishway or the partial or complete removal of a dam or other migration barrier) [factor; 3 levels: "0", "1", "2"]
Restoration_main_type		Main restoration type [factor, 3 levels: hydrological restoration=improved hydrological conditions, biotope enhancement=e.g. addition of gravel, large boulders or woody habitat elements, fishway=the construction, improvement or repair of a fishway or the partial or complete removal of a dam or other migration barrier]
Restoration_secondary_type	Secondary restoration type, when more than one type of restoration had been carrieed out in the BR [factor, 3 levels: hydrological restoration = improved hydrological conditions, biotope enhancement = e.g. addition of gravel, large boulders or woody habitat elements, fishway = the construction, improvement or repair of a fishway or the partial or complete removal of a dam or other migration barrier]
Waterbody_coresponds_to_bypassed_reach_-_good_match
							Indicates that the BR has a delineation with good correspondence to the delineation of a WFD (Water Framework Directive) waterbody. WFD waterbodies are the spatial units used in routine monitoring, management and Ecological Status or Ecological Potential classification in Sweden under the WFD. Good match indicates that the BR and the WFD waterbody are the same, or that there are only minor differences in their delination [factor, 2 levels: 1=yes or 0=no]
Waterbody_coresponds_to_bypassed_reach_-_poor_match
							Indicates that the BR has a delineation with poor correspondence to the delineation of a WFD (Water Framework Directive) waterbody. WFD waterbodies are the spatial units used in routine monitoring, management and Ecological Status or Ecological Potential classification in Sweden under the WFD. Poor match indicates that while there is some correspondence between BR and WFD waterbody the BR constitute only a minor part of a larger WFD waterbody [factor, 2 levels: 1=yes or 0=no]
Waterbody_coresponds_to_bypassed reach_-_no_match
							Indicates that the BR could not be safely matched against the delineation of a WFD (Water Framework Directive) waterbody. WFD waterbodies are the spatial units used in routine monitoring, management and Ecological Status or Ecological Potential classification in Sweden under the WFD. No match more specifically indicate that it could not be determined if the WFD waterbody at the location corresponded to the BR or if it corresponded to the tailrace channel of the hydropower station. A few BRs were also located in streams too small to be recognized as WFD waterbodies by the Swedish Water Authorities [factor, 2 levels: 1=yes or 0=no]
Connectivity_-_ecological_status
							Ecological status or ecological potential (the latter used for HMWBs) of the WFD waterbody with some correspondence to the BR based on the hydromorphological quality element connectivity [factor, 5 levels: B = bad Ecological status (ES) or Ecological Potential (EP), P = poor ES or EP, M = moderate ES or EP, G = good ES or EP, H = high ES or EP]
Hydrological_regime_-_ecological_status
							Ecological status or ecological potential (the latter used for HMWBs) of the WFD waterbody with some correspondence to the BR based on the hydromorphological quality element hydrological regime [factor, 5 levels: B = bad Ecological status (ES) or Ecological Potential (EP), P = poor ES or EP, M = moderate ES or EP, G = good ES or EP, H = high ES or EP]
Morphology_-_ecological_status
							Ecological status or ecological potential (the latter used for HMWBs) of the WFD waterbody with some correspondence to the BR based on the hydromorphological quality element morphology [factor, 5 levels: B = bad Ecological status (ES) or Ecological Potential (EP), P = poor ES or EP, M = moderate ES or EP, G = good ES or EP, H = high ES or EP]
Riparian_zone_-_ecological_status
							Ecological status or ecological potential (the latter used for HMWBs) of the WFD waterbody with some correspondence to the BR based on the hydromorphological quality element Riparian zone (or "neighborhood") [factor, 5 levels: B = bad Ecological status (ES) or Ecological Potential (EP), P = poor ES or EP, M = moderate ES or EP, G = good ES or EP, H = high ES or EP]
HMWB						Indicates whether the WFD waterbody with some correspondence to a BR has been classified as a Heavily Modified Waterbody (HMWB) (=1) or as a natural waterbody (=0) by the Swedish water authorities [factor, 2 levels: 1=yes or 0=no]

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REFERENCE INFORMATION
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Abbreviations:
BR = Bypassed reach at diversion hydropower station.
MMD = Mandated minimum discharge in Bypassed reach at diversion hydropower station.

Other abbreviations defined in the data file descripton under each respective column header.

Data sources:
This is an aggregated dataset, datasources for raw data provided below: 

Elevation, Elevation difference BR, Slope, Slope and river size indicates riffle/rapid dominance, Diversion dam height, Total head. Data source: National 2x2 m digital elevation model (“GSD-Höjddata grid 2+”, 2019) provided by the Swedish Land Survey (Lantmäteriet).
Stream order, MQ, Mean area specific discharge, MLQ, MHQ, MHQ/MQ, MLQ/MQ, Large river, Catchment area, Relative BR Catchment area, Anthropogenic land use, Slope and river size indicates riffle/rapid dominance, BR width, BR Area, Other water, Quantitative data on inflow from tributaries, Inflow from tributaries, Waterbody coresponds to bypassed reach - good match, Waterbody coresponds to bypassed reach - poor match, Waterbody coresponds to bypassed reach - no match. Data source: SMHIs Vattenwebb, version 2016: http://vattenwebb.smhi.se/
Proterozoic bedrock, Caledonian bedrock, Platformal sedimentary cover rocks. Data source: Swedish lithotectonic units (“Berggrund 1:1000000”, 2020) provided by Geological survey of Sweden.
Mud-morain and/or -silt soil, Peat soil. Data source: Swedish soil map (“Jordarter 1:1000000”, 2020) supplied by Geological survey of Sweden.
Slope and river size indicates riffle/rapid dominance, BR width, BR Area. Data source: SERS (Swedish Electrofishing RegiSter), retrieved 2020: http://www.slu.se/elfiskeregistret 
Number of different restoration measures, Restoration main type, Restoration secondary type. Data source: Swedish restoration database, retrieved 11.12.2020: https://www.atgarderivatten.se/
Waterbody coresponds to bypassed reach - good match, Waterbody coresponds to bypassed reach - poor match, Waterbody coresponds to bypassed reach - no match, Connectivity - ecological status, Hydrological regime - ecological status, Morphology - ecological status, Riparian zone - ecological status, HMWB. Data source: The Water Information System Sweden (VISS) database (https://viss.lansstyrelsen.se/, downloaded in 2020.12.02).
Verified info on MMD [categorical, 1=yes or 0=no]. MMD= mandated minimum discharge in the BR. We consulted with representatives from county administrative boards, water authorities, water regulation companies and/or relevant energy companies, and asked for information on weather the BR had a mandated minimum discharge or not. This column reflects the response frequency. 
MMD, MMDw proportion MQ, MMDMin = 0 m3/s, MMDMin >2 m3/s, MMDMin> MLQ, MMDMin, MMDMax. Data source: Consultation with representatives from county administrative boards, water authorities, water regulation companies and/or relevant energy companies.



