River water alkalinity, chloride-ion, conductivity, pH and nutrients data from the Frome Piddle; Pang Lambourn and Tern catchments, recorded between 2003 and 2006. River water samples were collected fortnightly at twenty three sites within these catchments and analysed for Alkalinity pH 4.5, Ammonia, Chloride-ion, Conductivity 20 deg C, Nitrate, pH, Phosphorus soluble reactive (SRP), Silicate reactive dissolved (SRD) and Sulphate. The samples were collected as part of the NERC funded Lowland Catchment Research (LOCAR) Programme to provide comparable baseline river water chemistry data across the LOCAR catchments. Full details about this dataset can be found at https://doi.org/10.5285/bb600a56-c9cf-4fca-b9be-be3de0039a79

This dataset is a compilation of water quality data for the River Frome catchment, Dorset, UK. The data have been sourced from the Environment Agency and from Wessex Water Ltd., the water utility company for the catchment area. The monitoring sites are specifically located in the lower part of the River Frome, between the Environment Agency gauging stations at Dorchester and East Stoke. The dataset includes water quality measurements for boreholes, sewage treatment work (STW) final effluents, tributaries, and main river channels. In total there are 21 monitoring sites. Water quality measurements date from 1976 to 2022. The main river channel and tributary sites are typically monitored on a monthly basis and the STW final effluents typically on a weekly basis. The borehole data can vary from weekly to monthly, depending on the determinand and borehole measured. Full details about this dataset can be found at https://doi.org/10.5285/9d98e1a7-7602-490f-9896-0eeed6eb1d40

Data consist of modelled estimates of observed/expected Biological Monitoring Working Party (an index for measuring the biological quality of rivers using selected families of macroinvertebrates as biological indicators) scores for freshwater streams across Great Britain (GB). The BMWP scores (1-10) are based on the principle that macroinvertebrates differ in their perceived sensitivity or tolerance to organic pollution (i.e. nutrient enrichment). Values greater than 1 indicate high water quality. Data pooled across two survey years (1998 and 2007) was used to model the relationships between headwater stream quality and catchment/stream characteristics for headwater streams across GB based on known relationships for headwater streams in Countryside Survey squares. Modelled estimates of stream water quality were based on a Boosted Regression Tree modelling approach . Full details about this dataset can be found at https://doi.org/10.5285/85e7beb6-e031-4397-a090-841b8c907d1b

This dataset describes the concentrations of photosynthetic pigments (Chlorophylls, carotenoids and phycocyanin) measured by HPLC and spectrophotometry in water samples of 20 lochs in Scotland. Data were collected between May and June 2022. Full details about this dataset can be found at https://doi.org/10.5285/7794cbfa-1d74-4885-b303-8c20f4608728

This dataset includes weekly data from monitoring of stream, rainfall and groundwater hydrochemistry in the Vyrnwy research catchment between 1994 and 2001. Data for over 50 chemical determinands are presented alongside data for some in-situ measurements such as water temperature. Full descriptions of the analytical methods used for each determinand is included. Intensive and long-term monitoring within the catchments underpins a wealth of hydrological and hydro-chemical research; other linked datasets include river flow, meteorology and a variety of detailed spatial datasets representing the topography, soils and rivers of the catchments. Monitoring is funded by the Centre for Ecology & Hydrology. Full details about this dataset can be found at https://doi.org/10.5285/68f4a12f-740d-4705-9c27-6a7fb7127046

Water quality data produced from rainfall, throughfall and stemflow samples collected within a beech stand at Black Wood in Hampshire, and an ash stand at Old Pond Close in Northamptonshire. Two studies were carried out in the early 1990s to examine water quality in relation to hydrological and pollution changes. Chemical analysis involved a combination of electrometric (pH), inductively-coupled plasma emission spectroscopy (most major, minor and trace elements), atomic absorption spectroscopy (potassium), ion chromatography (major anions and fluorine) and colourimetry (ammonium and silicon).

Discrete total alkalinity data for 13 sites in the Humber catchment sampled within the period 1993 to 1997 and 1996 to 1997 and for 3 sites from the Tweed catchment over the period 1994 to 1997, as part of the Land Ocean Interaction Study project (LOIS). Sites were sampled at regular weekly intervals and more intermittently during high flows (on average an extra sampling once a month per site). Samples were analysed on day of collection or on arrival at the laboratory using a Metrohm 702 Titrino autosampler. Full details about this dataset can be found at https://doi.org/10.5285/73a7ae36-2882-434f-a206-76b848e22d82

This dataset contains information about water quality based on faecal indicators at eighteen lakes in each of three lake districts: - Greater Glasgow conurbation, Scotland - Cumbria, NW England - Norfolk, E England. Lakes were sampled once in each of three seasons (spring, summer and autumn) in either 2016 (Norfolk) or 2017 (Cumbria and Greater Glasgow) with faecal indicators being quantified at three discrete sampling stations in each lake (>50m apart) and at three points at each station (i.e. nine samples per lake per sampling date). Faecal indicators were quantified based on standard dilution, membrane filtration and incubation, followed by colony counting. The data were collected to investigate the fine scale connectivity between Faecal Indicator Organisms (FIO) densities within water bodies and diffuse and point source inputs from the adjacent catchment and from biological vectors. They also provide an indication of the relative sources of variation in reported concentrations that is relevant for environmental regulatory purposes. The work was supported by the Natural Environment Research Council grant NE/N006437/1 (Hydroscape: connectivity x stressor interactions in freshwater habitats). Full details about this dataset can be found at https://doi.org/10.5285/5f988cd4-479d-4e35-8835-42f80ebc1698

This dataset contains high-resolution (5-minute) discharge, turbidity, suspended sediment concentration, and total phosphorus concentration data measured at three stream sites in the Littlestock Brook catchment (a tributary of the River Evenlode) from 2017 to 2021. The turbidity and concentration data were derived from a combination of instream sensors and lab-analysed water samples. Discharge data were derived using a stage-discharge rating curve constructed from manual measurements of flow velocity and water level sensor measurements. This dataset was collected by UKCEH as part of a hydrological monitoring programme for the Littlestock Brook Natural Flood Management scheme. There are some periods of data gaps within the timeseries as a result of sensor errors which have been excluded. These data may be used to calculate suspended sediment and phosphorus fluxes loads leaving the catchment. This work was supported by the Natural Environment Research Council (Grant NE/L002531/1). Full details about this dataset can be found at https://doi.org/10.5285/9f80e349-0594-4ae1-bff3-b055638569f8

Surface water quality data for the Conwy catchment, North Wales are presented. The data cover stream and estuary survey locations sampled manually from 2007 to 2011 at varying intervals between fortnightly and quarterly. Survey locations were selected as draining the main landscape classes in the catchment, which include upland (>300m) and lowland (<300m) environments under trees, moorland or improved agriculture. Also included are a suite of locations on the major rivers, and in the estuary. The purpose of the data is to provide support for estimating loads and testing hypotheses relating to the relationship between subcatchment properties and water quality, and the relative importance of mixing and in-stream processes in influencing downstream water quality. Streams draining peat, with high dissolved organic carbon concentrations, are well represented. Upland drainage is generally acidic, and lowland circum-neutral. The lowland rivers are not heavily contaminated with nutrients, although they show evidence of some loss of nitrates in particular. There is little industry in the catchment beyond agriculture and tourism, though there is some legacy contamination from metal mines in a small part of the catchment. Measurements are provided for major cations and anions, pH, alkalinity, DOC, Al, Fe and conductivity for most samples, with values for a wide range of trace elements for a limited number of samples. Full details about this dataset can be found at https://doi.org/10.5285/c53a1f93-f64c-4d84-82a7-44038a394c59