# What the water mouth is and how to find it > The water mouth is where water leaves the site downstream, read as a degree and mountain from the house centre. Find it at three scales: the grand scale from the region's real rivers and canals, the middle scale from terrain a few kilometres around, the small scale from road slope and drains by the house. Real water always comes first. **Goal:** Know which degree and mountain the site's water mouth falls in, and how sure that is — so the water method and every water reading start from the right point. ## What you need - The exact location of the site (pinned on the map) and the centre of the house. - The measured facing degree, to compare the water mouth with the sitting and facing. - Local knowledge: where the nearby river, canal or ditch flows, and which way the road in front slopes when it rains. ## Steps 1. **Choose the centre.** Use the centre of the house when reading a home, or the centre of the plot when reading land. Every water-mouth degree is read from this centre. 2. **Find the region's real water — grand scale.** Find the main river, canal, stream or lake near the site that the site's water drains into, and follow it downstream. The grand-scale water mouth is where that main flow leaves the area under study. This scale is the root. 3. **Read the terrain around the site — middle scale.** Within a few hundred metres to a few kilometres, look at the contour lines: surface water gathers along natural low channels and leaves on one side. If there is real water within that range, real water comes first. 4. **Look at the street water by the house — small scale.** Within a few tens of metres of the house, streets and drains are treated as watercourses. When it rains, the way water runs on the road is the way water leaves; where it leaves the front of the house is the small-scale water mouth. 5. **Read the degree and the mountain.** From the centre, read the degree to the water mouth and convert it to a mountain on the 24-mountain ring — for example, 208° falls in Wei. 6. **Judge the confidence.** Real water with a clear flow direction is reliable; gentle terrain or an almost flat road should be confirmed on site. Canals with sluices or pumps, and tidal areas, can reverse the flow. 7. **Check on site, then fix one point.** Go to the site and watch where water goes when it rains, and compare. Once sure, set one point as the main water mouth for the water method. ## Common mistakes - Taking the largest river in the region instead of the main river near the site that its water actually drains into. - Placing the water mouth where water arrives (upstream) instead of where it leaves. - Ignoring real water and looking only at the road in front. - Reading the degree from the gate or the edge of the plot instead of the centre of the house. - Relying fully on street water when the road is almost flat, without watching the water when it rains. ## Do it in Home Check 1. Open the Measure screen, pin the site on the satellite image, then tap the round Water Method button. 2. In Auto mode, Home Check finds the water mouth at the grand, middle and small scales and marks each on the map, with its degree, mountain, confidence and a short reason. 3. The grand-scale point is the main one for the water method; middle- and small-scale points are notes — if one looks more correct, tap “Use as main water mouth”. 4. Choose Manual to pin or drag the water mouth yourself; the system keeps your point. On very flat terrain the app asks you to choose the right point. 5. Turn on contour lines to see the high and low ground around the site yourself. ## Questions ### How is the water mouth different from incoming water? Incoming water is the side water flows towards the site from; the water mouth is the side it leaves by. On the same stream, upstream is the incoming water and downstream is the water mouth. Many water methods use the water mouth as their starting point. ### What makes a good water mouth? Classical texts prefer a water mouth that is closed and winding: water leaves slowly and out of sight, with mounds, trees or buildings guarding the exit so qi does not drain away. Where water arrives should be open, where it leaves should be closed — “the heavenly gate open, the earthly door shut”. ### What if there is no river near a townhouse? With no river or canal in range, the water mouth is found from the terrain — the natural drainage line where surface water gathers. In town, the streets and drains next to the house are street water, used at the small scale. ### Why do the three scales give three different points? Each scale looks at a different range: the grand scale follows the region's main water, the middle scale the lie of the land around the site, the small scale the road in front. Three different points are normal; the grand scale is the root and the smaller ones add detail. ### Can I pin the water mouth myself? Yes. Choose Manual, then pin or drag the point on the map; the system will not replace the point you set. Terms in this guide: [Water Mouth](https://myhomecheck.ai/learn/glossary/water-mouth) · [Water method](https://myhomecheck.ai/learn/glossary/water-method) · [Grand scale](https://myhomecheck.ai/learn/glossary/grand-scale) · [Middle scale](https://myhomecheck.ai/learn/glossary/middle-scale) · [Small scale](https://myhomecheck.ai/learn/glossary/small-scale) · [Street water](https://myhomecheck.ai/learn/glossary/street-water) · [Contours](https://myhomecheck.ai/learn/glossary/contour-lines) · [Bright hall](https://myhomecheck.ai/learn/glossary/bright-hall) --- Original page: https://myhomecheck.ai/learn/guides/find-the-water-mouth Other languages: [Tiếng Việt](https://myhomecheck.ai/vi/tri-thuc/huong-dan/thuy-khau-va-cach-xac-dinh/index.md) · [中文](https://myhomecheck.ai/zh/learn/guides/find-the-water-mouth/index.md) Updated: 2026-10-25