get_dams_by_canton

Retrieve Swiss dams under federal supervision for a specific canton using 2-letter canton codes. Provides up to 20 dams with basic details from official Swiss energy data.

Instructions

List all Swiss dams under federal supervision in a given canton. Returns up to 20 dams with basic details. Data source: Swiss Federal Office of Energy (SFOE) via swisstopo BGDI.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`canton`	Yes	Swiss canton 2-letter abbreviation code (e.g. 'VS' for Valais, 'GR' for Graubünden, 'BE' for Bern, 'UR' for Uri, 'TI' for Ticino, 'VD' for Vaud).

Implementation Reference

src/modules/dams.ts:309-360 (handler)

The handler implementation for the `get_dams_by_canton` tool, which validates the input canton code, fetches its bounding box, and filters dams within that area.

case "get_dams_by_canton": {
  const canton = args.canton as string;
  if (!canton?.trim()) {
    throw new Error("canton is required (2-letter code, e.g. 'VS', 'GR', 'BE')");
  }

  const cantonCode = canton.trim().toUpperCase();
  if (!/^[A-Z]{2}$/.test(cantonCode)) {
    throw new Error("canton must be a 2-letter Swiss canton code (e.g. 'VS', 'GR', 'BE', 'ZH')");
  }

  // Get canton bounding box
  const bbox = await fetchCantonBbox(cantonCode);
  if (!bbox) {
    throw new Error(`Unknown canton code: "${cantonCode}". Use standard 2-letter Swiss canton abbreviations (VS, GR, BE, UR, TI, VD, etc.)`);
  }

  const [xmin, ymin, xmax, ymax] = bbox;

  // Fetch all dams with geometry to filter by canton bbox
  const allDams = await findDams("%", "damname", true);

  // Filter dams whose coordinates fall within the canton bbox
  const cantonDams = allDams.filter((dam) => {
    const x = dam.geometry?.x;
    const y = dam.geometry?.y;
    if (x == null || y == null) return false;
    return x >= xmin && x <= xmax && y >= ymin && y <= ymax;
  });

  if (!cantonDams.length) {
    return JSON.stringify({
      canton: cantonCode,
      dams: [],
      count: 0,
      message: `No dams found in canton ${cantonCode}. This canton may not have any dams under federal supervision.`,
      source: `${BASE}/find?layer=${DAMS_LAYER}`,
    }, null, 2);
  }

  const limited = cantonDams.slice(0, MAX_RESULTS);
  const formatted = limited.map((dam) => formatDamSummary(dam, cantonCode));

  const response = {
    canton: cantonCode,
    dams: formatted,
    count: formatted.length,
    total_in_canton: cantonDams.length,
    note: cantonDams.length > MAX_RESULTS
      ? `Showing first ${MAX_RESULTS} of ${cantonDams.length} dams in canton ${cantonCode}.`
      : undefined,
    source: `${BASE}/find?layer=${DAMS_LAYER}`,

src/modules/dams.ts:216-231 (schema)

The tool definition and input schema for `get_dams_by_canton`.

{
  name: "get_dams_by_canton",
  description:
    "List all Swiss dams under federal supervision in a given canton. Returns up to 20 dams with basic details. Data source: Swiss Federal Office of Energy (SFOE) via swisstopo BGDI.",
  inputSchema: {
    type: "object",
    required: ["canton"],
    properties: {
      canton: {
        type: "string",
        description:
          "Swiss canton 2-letter abbreviation code (e.g. 'VS' for Valais, 'GR' for Graubünden, 'BE' for Bern, 'UR' for Uri, 'TI' for Ticino, 'VD' for Vaud).",
      },
    },
  },
},

mcp-swiss