When Should You Drain and Refill an Inground Pool in Virginia?

One of the most common questions pool owners ask is whether they need to drain the pool each winter. The answer for Virginia is almost always no. Winterization in this climate involves dropping the water level a few inches, blowing out the plumbing lines, and plugging the returns, not emptying the pool. A fully drained pool in Virginia's winters creates more risk than it solves.

Why Pools Should Not Be Emptied for Winter

An inground pool that has been fully emptied is at risk from the surrounding soil. Even in Virginia's relatively mild winters, the weight of saturated soil pressing against an empty shell can cause damage in both fiberglass and gunite pools. The hydrostatic pressure from groundwater, which is absent when the pool is full because the water weight counteracts it, can cause an empty fiberglass shell to buckle or pop out of the ground. An empty gunite pool can develop cracks from soil pressure and thermal stress.

Virginia's winterization approach keeps the pool water level at or slightly below the return and skimmer lines, not empty. The water weight stays in the pool to counteract soil and groundwater pressure. The plumbing is cleared to prevent freeze damage. The pool sits that way until spring opening.

For the full procedure on winterizing your pool properly in Virginia, the page on how to winterize a pool in Virginia covers every step of the seasonal close-down process.

When a Full Drain Is Necessary

A complete drain and refill is warranted in specific situations. The most common is chemistry correction: when total dissolved solids (TDS), cyanuric acid (stabilizer), or calcium hardness have built up over years of chemical additions to levels that cannot be corrected by dilution alone, a fresh fill is the most practical solution. Virginia's moderate pool season means these levels build more slowly than in year-round climates, but they do accumulate over time.

High cyanuric acid is the most frequent driver of a drain decision in Virginia pools. Cyanuric acid is added to outdoor pools as a stabilizer that protects chlorine from UV degradation. It does not leave the water on its own; the only way to lower it is to dilute the water. When CYA levels climb above 80 to 100 parts per million, chlorine efficiency drops significantly and maintaining proper sanitation becomes difficult. If partial water replacement through splash-out and rainfall does not bring the level down over a season, a controlled drain-and-refill resets it.

The Three to Seven Year Window

For a well-managed pool in Virginia, a full drain is typically needed every three to seven years. The range reflects differences in local water chemistry, bather load, chemical management, and how much fresh water enters the pool through rainfall and splash-out. A heavily used pool with heavy chemical additions will accumulate TDS faster than a lightly used one. Routine water testing tells you when the numbers are approaching the threshold where a fresh fill makes more sense than continued correction.

Draining for Resurfacing or Repairs

A gunite pool that needs interior resurfacing must be drained completely to allow the old plaster or pebble finish to be removed and the new finish to be applied. This is the most predictable reason for a full drain, occurring every 10 to 15 years on average for a gunite pool. Structural repairs to the pool shell, returns, or main drain also require draining to the affected area or fully, depending on the scope of the repair.

For a look at what gunite pool resurfacing involves and what typically triggers it, the page on pool resurfacing for gunite pools in Virginia covers the process and timeline in detail.

When to Drain: Temperature Matters

Draining a pool should happen in mild weather, not during a freeze or a heat wave. In freezing conditions, an empty gunite pool can develop stress cracks from thermal contraction. In a Virginia summer heat wave, an empty gunite shell exposed to direct sun can develop shrinkage cracks as the concrete heats and dries rapidly. The practical drain windows are spring before the pool season opens and fall after it closes, when temperatures are moderate.

For fiberglass pools, the risk of hydrostatic damage from a rising water table is the main weather concern. Drain in a dry period, not after heavy rain when the water table may be elevated. If you know your lot has a high water table, consult with your builder before draining.

How to Discharge Pool Water

Pool water is chemically treated and should not be directed into storm drains, waterways, or sensitive landscape areas. The best discharge path is a sanitary sewer cleanout, a utility tap, or a designated point away from storm drainage. Some Virginia localities have specific rules about where pool water can be discharged. Before draining, lower chlorine levels by stopping additions and letting sunlight reduce the concentration over a few days, then run the drain to an appropriate discharge point.

After the Drain: What to Check

Before refilling, inspect the pool interior for any cracks, damaged plumbing fittings, or worn surfaces that are accessible only when the pool is empty. Minor cracks in gunite can be patched before refill. This is the opportunity to address small issues before they become bigger problems that require another drain to reach.

For ongoing pool chemistry management that can extend the time between full drains, the page on pool chemistry basics for beginners explains how to keep water balanced through the season.

Have a pool question or need a consultation? Get in touch with K&D and we will help you assess whether your pool's chemistry calls for a fresh fill or continued correction.