Watertown Municipal Utilities interconnection application

Watertown Municipal Utilities is a municipal utility serving 11,775 residential customers in South Dakota (EIA-861, 2025). Gridpol files Watertown Municipal Utilities interconnection applications for licensed installers – solar, storage and EV chargers – with single-line diagram and site plan, unlimited for $500 a month.

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South Dakota’s commission rule (ARSD 20:10:36 (Small Generator Interconnection)) does not bind municipal utilitys; Watertown Municipal Utilities sets its own interconnection policy. We confirm its form on the first project. Electric cooperatives and municipal utilities are not rate-regulated by the PUC and set their own interconnection and buyback policies.

Watertown Municipal Utilities at a glance

Utility

Watertown Municipal Utilities

Type

Municipal utility

EIA utility ID

20187

Residential customers

11,775 (EIA-861, 2025)

Net-metered residential customers

none reported

Service territory

1 county in South Dakota

Documents Watertown Municipal Utilities asks for

Interconnection application formFilled in by us from your project data in the utility’s portal or on its form. Gridpol prepares this.
Single-line diagram (one-line)Drawn by us from your equipment data: modules, strings, inverter, battery, disconnects, point of interconnection, meter. Gridpol prepares this.
Site plan / site layoutDrawn by us from your roof sketch or photos: array, inverter, battery, disconnect, meter and main panel locations. Gridpol prepares this.
PV module spec sheetManufacturer data sheet of the modules.
Inverter spec sheetManufacturer data sheet (string inverter, microinverter or hybrid inverter).
Customer signatureThe account holder signs the application or authorization. We send the signature link.
Recent electric billName, service address, account and meter number must match the application.
Final inspection sign-offApproved electrical inspection from the authority having jurisdiction after installation.

Typical documents for US utilities – not yet verified for Watertown Municipal Utilities. We confirm Watertown Municipal Utilities’s exact list on the first project.

South Dakota interconnection rule

Commission

South Dakota Public Utilities Commission

Interconnection rule

ARSD 20:10:36 (Small Generator Interconnection) – Small Generator Facility Interconnection · source

Applies to

Public utilities (PUC rate-regulated IOUs: Xcel/NSP, Black Hills, NorthWestern, MDU, Otter Tail) for facilities <=10 MW not under FERC/RTO jurisdiction

Application form

Commission tier application forms (application forms available from the commission, 20:10:36:33); certificate of completion; interconnection agreement

Timelines

Tier 1: acknowledgment within 3 business days, completeness within 10 BD, applicant 20 BD to cure, review within 15 BD after complete (20:10:36:33). Completion requires passed screens, code inspector approval, witness test if done, certificate of completion, executed agreement (20:10:36:34).

Fees

Tier 1 $50; Tier 2 $50 + $1/kW up to $500; Tier 3 and 4 $100 + $2/kW up to $1,000 (20:10:36:06).

Insurance

Tier 1: proof of adequate homeowners/general/commercial liability; Tier 2 up to $500,000; Tiers 3-4 up to $1,000,000 at utility request (20:10:36:26). Endorsements (utility additional insured etc.) not required for residential <=10 kW (20:10:36:27).

External disconnect

Only if required by the utility: primary-line lockable visible-break device; secondary-line lockable device with clearly indicated status; lockbox alternative (20:10:36:15).

Export compensation

None statewide
No statewide net metering rule; compensation per utility tariff (e.g. avoided-cost/PURPA).

Not bound by the rule

Electric cooperatives and municipal utilities are not rate-regulated by the PUC and set their own interconnection and buyback policies.

ARSD 20:10:36 chapter index: https://sdlegislature.gov/api/Rules/20:10:36.html (retrieved 2026-11-13)
ARSD 20:10:36:06 Application fees: https://sdlegislature.gov/api/Rules/20:10:36:06.html (retrieved 2026-11-13)
ARSD 20:10:36:26 Insurance amounts: https://sdlegislature.gov/api/Rules/20:10:36:26.html (retrieved 2026-11-13)
ARSD 20:10:36:33 Tier 1 review procedures: https://sdlegislature.gov/api/Rules/20:10:36:33.html (retrieved 2026-11-13)

Other utilities in South Dakota

All South Dakota utilities →

Gridpol Unlimited

$500 / month

Unlimited interconnection applications. 12-month agreement, signed online. The agreement starts the day you sign; first invoice right away, then monthly.

Unlimited interconnection applications
Single-line diagram and site plan for every application
Pre-submission check against the utility’s requirements
Homeowner e-signature link for the authorization
Filing in your utility portal accounts or by the utility’s method
Utility questions, corrections and resubmissions
Follow-up through approval, inspection and PTO
Customer list, exports, API and webhooks

Get started

Applications are typically submitted within 2 business days after complete documents. Utility review times are set by each utility.