#water

Irrigation-design maths as an API, computed locally and deterministically — the sprinkler numbers a landscaper, irrigation tech or gardener sizes a system with. The precip-rate endpoint gives the precipitation rate in inches per hour from the flow and spacing: PR = 96.25 × GPM per head ÷ the area each head waters (head spacing × row spacing in feet), where 96.25 is the in/hr one gallon-per-minute makes over a square foot — three-GPM heads on a 15 × 15 ft grid lay down about 1.28 in/hr. The runtime endpoint turns a target water depth into a run-time: depth ÷ precipitation rate, divided by the system efficiency because no system is perfectly even, so applying a half-inch at 1.28 in/hr takes about 23 minutes at full efficiency, longer with real-world uniformity. The zone endpoint sizes a valve zone: maximum heads = available flow ÷ each head's GPM, rounded down so you never starve the line — 13 GPM drives five 2.6-GPM heads with nothing to spare. Everything is computed locally and deterministically, so it is instant and private. Ideal for irrigation and landscaping apps, sprinkler-design and contractor tools, smart-controller schedulers, and garden-planning sites. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 compute endpoints. For evapotranspiration or weather use a weather API; for material volume use a mulch API.

api.oanor.com/irrigation-api

Rainwater-harvesting maths as an API, computed locally and deterministically. The harvest endpoint works out how much water a roof collects from a given rainfall — from the catchment (roof plan) area, the rainfall depth and a runoff coefficient it returns the harvested volume in litres, US and UK gallons and cubic metres, using the identity that 1 mm of rain over 1 m² collects 1 litre before losses. The runoff coefficient can be given directly or looked up from the roof type (smooth metal collects the most at ~0.9, green roofs the least at ~0.3). The demand endpoint sizes a storage tank from a daily demand (given directly or as people × litres per person) and the length of the dry spell you want to cover, and — if you also pass the annual rainfall and roof area — checks whether a year of harvest can meet a year of demand. The firstflush endpoint sizes a first-flush diverter, the volume of dirty initial rain to discard. Areas accept square metres or square feet (or length × width), rainfall accepts millimetres, centimetres or inches. Everything is computed locally and deterministically, so it is instant and private. Ideal for sustainability and off-grid apps, plumbing and landscaping tools, smart-home water systems, and construction planners. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 4 endpoints. This is rainwater catchment maths; for roof pitch and area geometry use a roofing API and for general construction material quantities use a construction API.

api.oanor.com/rainwater-api

Water-hardness maths as an API, computed locally and deterministically. The convert endpoint converts a hardness value between all the common units — parts per million / milligrams per litre as calcium carbonate, grains per US gallon, German degrees (°dH), French degrees (°f), English or Clark degrees, and millimoles per litre — passing everything through ppm (1 gpg = 17.118 ppm, 1 °dH = 17.848, 1 °f = 10, 1 °Clark = 14.254), and classifies the result. The classify endpoint labels a value as soft, moderately hard, hard or very hard on the USGS/WHO scale. The softener endpoint sizes a water softener: from the hardness and the household water use it works out the grains of hardness removed per day and the grain capacity needed between regenerations. Everything is computed locally and deterministically, so it is instant and private. Ideal for water-treatment and plumbing tools, aquarium and pool apps, appliance and softener sizing, and home and lab software. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is water-hardness conversion; for general unit conversion use a unit-conversion API and for swimming-pool dosing use a pool API.

api.oanor.com/hardness-api

Swimming-pool maths as an API, computed locally and deterministically. The volume endpoint computes the water volume of a rectangular, round or oval pool — in litres, US gallons and cubic metres — from the dimensions and either an average depth or separate shallow and deep depths (it averages them), in feet or metres. The dose endpoint computes how much of a chemical to add to raise a level by a target ppm: give the pool volume and the desired increase, and either the product strength percent or a preset (cal-hypo, dichlor, trichlor, liquid chlorine, bleach), and it returns the amount in grams, kilograms, ounces and pounds. The salt endpoint computes the salt needed to reach a target salinity in a saltwater pool from the current and target ppm, in kilograms and pounds (and 40 lb bags). Everything is computed locally and deterministically, so it is instant and private. Dosing depends on the actual product strength and your test readings — always follow the product label, add in stages and re-test before adding more. Ideal for pool-service and maintenance apps, pool-builder and retailer tools, and smart-pool and home-automation systems. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is pool maths; for general volume or unit conversion use a unit-conversion API.

api.oanor.com/pool-api

Live river and stream conditions from the USGS Water Services network. The catalogue of 16,900+ active US streamflow gauges is searchable by name, state or coordinate; the live endpoint returns the latest observation for any gauge: streamflow / discharge (in cubic feet per second and m³/s) and gauge height (in feet and metres), with the station name, observation time and coordinates. Find the gauges nearest any lat/lon. Ideal for flood monitoring, hydrology, whitewater/fishing & recreation apps, drought tracking and environmental dashboards.

api.oanor.com/streamflow-api