REBECCA FRANK DALLET, J.
*49*179¶ 1 Philip and Terrie Myers seek review of an unpublished per curiam decision of the court of appeals1 affirming in part and reversing in part the circuit court.2 The Myers seek review of the Wisconsin Department of Natural Resources' (DNR) unilateral amendment to their pier permit.
¶ 2 In 2001, the Myers were granted a permit by the DNR and built a pier at their waterfront property on Lake Superior. In 2012 and 2013, the DNR received *180complaints from a neighboring property owner about the Myers' pier. The DNR conducted an investigation and requested that the Myers substantially modify their pier. The Myers declined to make the DNR's proposed changes. The DNR then issued a "Notice of Pending Amendment," held a public informational hearing, and ultimately issued a formal permit amendment requiring the Myers to significantly change their pier in one of two ways.
¶ 3 The Myers declined to comply with the DNR's permit amendment and instead filed a petition for Wis. Stat. ch. 227 (2015-16)3 judicial review in the Ashland County Circuit Court. The circuit court denied the Myers' petition, finding that the DNR had the authority to issue an amendment to the Myers' pier permit. The circuit court then remanded the case to the DNR, finding that more fact-finding was needed as to the applicability of several statutory exemptions which could bar the DNR's action. Both parties appealed the circuit court's decision.
¶ 4 The court of appeals affirmed the circuit court's conclusion that the DNR had the authority to issue the Myers' permit amendment. The court of appeals reversed the circuit court as to the statutory exemptions, concluding as a matter of law that the statutory exemptions did not apply.
¶ 5 On petition to this court, the Myers seek review of three issues: (1) whether the DNR had the authority to amend their permit; (2) whether two exemptions in Wis. Stat. § 30.12(1k) barred the DNR's actions; and (3) whether the court of appeals could rely on "implicit findings" made by the DNR at a public *181informational hearing to conclude that the statutory exemptions in § 30.12(1k) did not apply to the Myers' pier.
¶ 6 We conclude that the DNR did not have the authority to unilaterally amend the Myers' permit. We therefore reverse the decision of the court of appeals. Because the DNR did not have the authority to amend the Myers' permit, we need not reach the issues related to the application of the statutory exemptions set forth in Wis. Stat. § 30.12(1k).
I. FACTUAL BACKGROUND AND PROCEDURAL POSTURE
¶ 7 The Myers own waterfront property on Madeline Island on Lake Superior. In December 1999, the Myers filed an application, pursuant to Wis. Stat. § 30.12, to construct a rock-filled pier next to the remnants of a dock that had been built on their property in the 1930s. The DNR received several objections to the Myers' application. The objectors were concerned that the proposed pier would result in beach erosion and other shoreline changes *50related to "littoral drift," the process of moving sediment along the shore.
¶ 8 In June 2001, the DNR held a contested hearing on the Myers' permit application. On July 23, 2001, an administrative law judge (ALJ) granted the Myers "a permit under Wis. Stat. § 30.12 for the construction of a structure." The permit granted the Myers permission to construct a pier consisting of "rock-filled cribs 10 feet in width extending 70 feet waterward from an existing 16-foot crib." The pier design also included a 14-foot L-extension with a 12-foot "flow-through opening" that would allow water *182and sediment to flow underneath and through the structure. The ALJ concluded that it was "unlikely that there [would] be detrimental impacts relating to shoreline alterations." However, the ALJ found that it was not always possible to predict the impact of a particular structure so he included the following language in the Myers' permit: "[t]he authority herein granted can be amended or rescinded if the structure becomes a material obstruction to navigation or becomes detrimental to the public interest" ("Condition 1"). The ALJ explained that Condition 1 would be "protective of unexpected impacts on neighboring properties relating to sand accumulation or beach starvation."
¶ 9 The Myers completed construction of their pier in October 2001 in accordance with the specifications set forth in the permit. In 2012 and 2013, the DNR received complaints from a neighboring riparian property owner who alleged that there was shoreline erosion and a loss of riparian property4 due to the Myers' pier.
¶ 10 As a result of these complaints, the DNR conducted an investigation and consulted with a coastal engineer, Gene Clark. Clark visited the Myers' property and wrote a report, detailing his opinion as to the effects of the Myers' pier. Clark ultimately concluded that because of "complexity of the mix of older and newer structures," as well as the fact that some littoral material "existed with just the older structures in place several decades ago," it was "extremely difficult to estimate how much if any additional littoral *183material trapping is occurring due only to the [Myers'] newer pier structures." The DNR sent the Myers a letter in July 2013, informing them that their pier was not in compliance with the 2001 permit. The DNR informed the Myers that the flow-through opening was not functioning as intended. Further, the DNR required the Myers to remove the two 24-foot cribs and replace the "bridge" between the crib and the L with a different system that allowed for the free movement of water and sediment. The Myers declined to institute the DNR's proposed changes.5
¶ 11 In November 2013, the DNR issued a Class I "Notice of Pending Amendment" indicating that it proposed to amend the Myers' 2001 permit to require expansion of the flow-through opening from 12 to 60 feet. The notice requested public comment on the proposed amendment. On January 7, 2014, the DNR held a public informational hearing on the amendment. An engineer testified in support of the Myers at the public informational hearing, asserting that the amendment was not supported by the site observations or any relevant technical evaluation.
*51¶ 12 On April 21, 2015, 14 years after the original permit was issued, and 15 months after the public hearing, the DNR issued an amendment which required the Myers to modify their pier in one of two ways. The DNR gave the Myers the following options: (1) remove two waterward cribs on the main stem of the pier to expand the flow-through opening from 12 to 60 feet; or (2) provide the DNR with certified engineering plans that depict an alternative opening to allow *184for the free movement of water and sediment. The DNR asserted that it had authority under Wis. Stat. § 30.12(3m) to issue this permit amendment. The DNR gave the Myers 30 days to decide on a modification option and 18 months to complete that modification.
¶ 13 The Myers filed a petition for Wis. Stat. ch. 227 judicial review in the Ashland County Circuit Court.6 In that action, the Myers asserted that: (1) the DNR lacked authority to apply for and grant itself an amendment; (2) their pier was exempt from permit requirements, pursuant to Wis. Stat. § 30.12(1k)(b) ; (3) their pier was exempt from enforcement actions, pursuant to § 30.12(1k)(cm) ; and (4) the evidence did not support the DNR's decision to amend their permit.
¶ 14 The circuit court rejected the Myers' claim that the DNR lacked the authority to amend their 2001 permit. However, the circuit court remanded the case to the DNR for additional factual development as to whether the exemptions in Wis. Stat. § 30.12(1k) applied to the Myers' pier. The Myers appealed the circuit court's decision. The DNR cross-appealed the circuit court's decision to remand for additional fact-finding.
¶ 15 The court of appeals issued a decision affirming in part and reversing in part the circuit court. The court of appeals affirmed the circuit court's holding that the DNR had the authority to amend the permit and reversed the circuit court's remand for additional fact-finding. The court of appeals concluded as a matter of law that neither of the exemptions *185applied because of "implicit findings" made by the DNR at the public informational hearing.
¶ 16 The Myers raise three issues on appeal to this court: (1) whether the DNR had authority to amend their permit; (2) whether two exemptions in Wis. Stat. § 30.12(1k) barred the DNR's actions; and (3) whether the court of appeals could rely on "implicit findings" made by the DNR at a public informational hearing to conclude that the statutory exemptions in § 30.12(1k) did not apply to the Myers' pier.
II. STANDARD OF REVIEW
¶ 17 On a Wis. Stat. ch. 227 appeal we review the decision of the agency, not the circuit court. Hilton ex rel. Pages Homeowners' Ass'n v. DNR, 2006 WI 84, ¶ 15, 293 Wis. 2d 1, 717 N.W.2d 166. We have ended our practice of deferring to administrative agencies' conclusions of law. Tetra Tech EC, Inc. v. DOR, 2018 WI 75, ¶ 3, 382 Wis. 2d 496, 914 N.W.2d 21. Instead, we give "due weight" to the experience, technical competence, and specialized knowledge of an administrative agency in evaluating the persuasiveness of the agency's argument. Id. When a determination of the scope of an agency's power is central to resolution of the controversy, as in this case, we independently decide the extent of the agency-authority that the statute *52provides. See Rock-Koshkonong Lake Dist. v. DNR, 2013 WI 74, ¶¶ 61-62, 350 Wis. 2d 45, 833 N.W.2d 800.
¶ 18 This case involves interpretation of Wis. Stat. ch. 30, which regulates navigable waters. Statutory interpretation is a question of law that this court *186reviews de novo. Noffke ex rel. Swenson v. Bakke, 2009 WI 10, ¶ 9, 315 Wis. 2d 350, 760 N.W.2d 156. The purpose of statutory interpretation is to "determine what the statute means so that it may be given its full, proper, and intended effect." State ex rel. Kalal v. Circuit Court for Dane Cty., 2004 WI 58, ¶ 44, 271 Wis. 2d 633, 681 N.W.2d 110. Statutory interpretation begins with the language of the statute. Kalal, 271 Wis. 2d 633, ¶ 45, 681 N.W.2d 110. Statutory language is "given its common, ordinary, and accepted meaning," unless there are technical or specially-defined words or phrases. Id., ¶ 45. If the statutory language yields a "plain, clear statutory meaning, then there is no ambiguity," and there is no need to consult extrinsic sources of interpretation. Id., ¶ 46.
III. ANALYSIS
¶ 19 This dispute centers around whether the DNR had authority to unilaterally amend the Myers' permit 14 years after their pier was placed. Although not explicitly argued by the DNR, the court of appeals held that the DNR had the authority to amend the Myers' permit by reserving to itself that authority in Condition 1. Before this court, the DNR cites to two statutory authorizations of power in support of its ability to amend the Myers' permit: Wis. Stat. § 30.12(3m)(d)2. and Wis. Stat. § 30.2095(2). The DNR asserts that § 30.12(3m)(d)2. statutorily authorizes the placement of Condition 1 in the Myers' permit. Alternatively, the DNR argues that even absent Condition 1, § 30.2095(2) provides it with the authority to modify or rescind the permit for "good cause" because the Myers' permit never expired. We address each argument in turn.
*187A. Reservation of Authority
¶ 20 We first address the court of appeals' holding that the DNR could, absent statutory authorization, reserve to itself the authority to amend the Myers' permit in Condition 1. See Myers v. DNR, No. 2016AP1517, unpublished slip op., ¶ 14, 2017 WL 3730420 (Wis. Ct. App. Aug. 29, 2017). Condition 1 reads "[t]he authority herein granted can be amended or rescinded if the structure becomes a material obstruction to navigation or becomes detrimental to the public interest." The court of appeals looked to the language of Condition 1 and held that no other explicit grant of authority was necessary. See Myers, No. 2016AP1517, ¶ 14 & n.2. The court of appeals also placed an additional burden on the Myers to cite to law indicating that the DNR was unable to reserve to itself such authority. See Myers, No. 2016AP1517, ¶ 14 & n.2. The court of appeals further determined that the Myers "agreed to the condition allowing amendment by accepting the permit."7 See Myers, No. 2016AP1517, ¶ 14.
¶ 21 We conclude that the court of appeals erred in holding that Condition 1 in and of itself provided the DNR the authority to amend the Myers' permit. It is important to remember that administrative agencies are creatures of the legislature. An administrative agency has only those powers expressly conferred or necessarily implied by the statutory provisions under which it operates. See *53*188Kimberly-Clark Corp. v. Public Serv. Comm'n of Wis., 110 Wis. 2d 455, 461-62, 329 N.W.2d 143 (1983) ; Brown Cty. v. DHSS, 103 Wis. 2d 37, 43, 307 N.W.2d 247 (1981) ; American Brass Co. v. Wisconsin State Bd. of Health, 245 Wis. 440, 448, 15 N.W.2d 27 (1944). We resolve any reasonable doubt pertaining to an agency's implied powers against the agency. See Kimberly-Clark Corp., 110 Wis. 2d at 462, 329 N.W.2d 143. We conclude that absent statutory authorization, Condition 1 in and of itself cannot provide the DNR the authority to amend the Myers' permit. We next turn to whether the DNR had statutory authorization to amend the Myers' permit.
B. Wisconsin Stat. § 30.12(3m)(d)2.
¶ 22 The DNR argues that it had statutory authority pursuant to Wis. Stat. § 30.12(3m)(d)2. to insert Condition 1 in the Myers' 2001 permit because that condition implemented the criteria under § 30.12(3m)(c)1.-3. Section 30.12(3m)(d)2. allows the DNR to "promulgate rules that limit the issuance of individual permits for solid piers."8 The statute further explains that these rules "may establish reasonable conditions to implement the criteria under par. (c)1. to 3." Section 30.12(3m)(c) reads:
(c) The department shall issue an individual permit to a riparian owner for a structure ... if the department finds that all of the following requirements are met:
1. The structure or deposit will not materially obstruct navigation.
2. The structure or deposit will not be detrimental to the public interest.
3. The structure or deposit will not materially reduce the flood flow capacity of a stream.
*189¶ 23 The DNR likens Condition 1 to a "reasonable condition[ ] to implement the criteria under par. (c)1. to 3.," pursuant to Wis. Stat. § 30.12(3m)(d)2. The DNR reads the language of § 30.12(3m)(c) as imposing a requirement that a permit continuously satisfy the criteria in paragraphs 1. through 3. Therefore, according to the DNR, when, if at all, a permit fails to satisfy all three criteria in § 30.12(3m)(c)1.-3., the DNR may amend or rescind the permit pursuant to Condition 1.
¶ 24 There is no support in the plain language of Wis. Stat. ch. 30 for the DNR's claim that a pier permit carries with it an ongoing requirement to satisfy the criteria in Wis. Stat. § 30.12(3m)(c)1.-3.9 The language of § 30.12(3m)(c)1.-3. explicitly uses the past tense "met" when it lists the requirements for granting a permit, thus signifying that the conditions must be fulfilled before the permit is granted. Courts must avoid interpretations that require inserting words into statutes. See Heritage Farms, Inc. v. Markel Ins. Co., 2009 WI 27, ¶ 14, 316 Wis. 2d 47, 762 N.W.2d 652 ; C. Coakley Relocation Sys., Inc. v. City of Milwaukee, 2008 WI 68, ¶ 24, 310 Wis. 2d 456, 750 N.W.2d 900. There is no language in ch. 30 that requires a permit to continuously satisfy the criteria in § 30.12(3m)(c)1.-3. and we will not read such language into the statute.
¶ 25 The DNR also argues that "the entire tenor" and "spirit" of Wis. Stat. ch. 30 suggests that a permit includes a requirement *54to continuously satisfy *190the criteria in Wis. Stat. § 30.12(3m)(c)1.-3. When pressed at oral argument, the DNR cited to several sections of ch. 30 that allegedly illustrate the legislature's intent that permits continue to govern piers indefinitely. This brings us to the question of whether a permit issued under § 30.12 is akin to a building permit or is a permit governing possession. This question is intertwined with the DNR's alleged second statutory authorization of power, Wis. Stat. § 30.2095.
C. Wisconsin Stat. § 30.2095
¶ 26 Apart from the alleged authorization given to the DNR in Wis. Stat. § 30.12(3m)(d)2., the DNR relies on Wis. Stat. § 30.2095(2) as a separate avenue of independent authority to amend the Myers' permit. Section 30.2095(2) reads: "[f]or good cause, the department may modify or rescind any permit or contract issue under ss. 30.01 to 30.29 before its expiration." The DNR's argument rests on the premise that because the Myers' pier was completed within three years, the Myers' permit never expired. Therefore, the DNR could modify or rescind the Myers' permit at any time pursuant to § 30.2095(2) for "good cause." We must first address the parties' dispute as to whether the permit was akin to a building permit or is a permit governing possession, and, accordingly when, if at all, the Myers' permit expired.
¶ 27 The Myers contend that their permit was akin to a building permit and that, according to its terms, it expired on July 23, 2004, three years after its issuance. The DNR asserts, and the court of appeals agreed, that because the pier was completed within the time limit set forth in the permit, the Myers' permit *191did not expire. As additional support for its position, the DNR asserts that a permit controls ongoing maintenance and use of a pier, even after its placement.10
¶ 28 We agree with the Myers' interpretation and conclude that, based upon a plain reading of the language of Wis. Stat. ch. 30, a permit issued under Wis. Stat. § 30.12 is akin to a building permit.
¶ 29 The Myers were granted "a permit under Wis. Stat. § 30.12 for the construction of a structure" that expired "three years from the date of [July 23, 2001], if the structure is not completed before then." This language comports with the language set forth in Wis. Stat. § 30.2095(1)(a) which provides, in pertinent part, that a permit "issued under ss. 30.01 to 30.29 ... is void unless the activity or project is completed within 3 years after the permit or contract was issued." Section 30.2095(1)(b) allows for an extension of the permit for "no longer than an additional 5 years if the grantee requests an extension prior to expiration of the initial time limit."
¶ 30 "[S]tatutory language is interpreted in the context in which it is used; not in isolation but as part of a whole; in relation to the language of surrounding or closely-related statutes; and reasonably, to avoid absurd or unreasonable results." Kalal, 271 Wis. 2d 633, ¶ 46, 681 N.W.2d 110. By employing the phrase "unless the activity or project is completed" in Wis. Stat. § 30.2095(1)(a) as a reference point for when the permit becomes void, the legislature expressed its intent that the permit be for the completion of the activity or project for which *192the permit was granted, i.e., the placement of a pier. When § 30.2095(1) is read in conjunction with § 30.2095(2), it is clear that the "expiration" *55for the modification of a permit discussed in § 30.2095(2) is the earlier of the expiration date of the permit or the actual date when pier placement was completed.11
¶ 31 According to the DNR and the court of appeals, if pier placement is complete within the timeframe determined by Wis. Stat. § 30.2095(1)(a), the permit never expires. If that were the case, the phrase "before its expiration" in § 30.2095(2) becomes superfluous since the DNR could "[f]or good cause" modify or rescind any non-void permit or contract at any time.
¶ 32 It is also noteworthy that the legislature made a distinction between the term "void," as used in Wis. Stat. § 30.2095(1)(a), and the term "expiration," as used in § 30.2095(1)(b) and (2). These terms are presumed to have distinct meanings. See Johnson v. City of Edgerton, 207 Wis. 2d 343, 351, 558 N.W.2d 653 (Ct. App. 1996). Given its plain meaning, where a grantee needs additional time to complete a project, he or she may ask to extend the expiration date of a permit pursuant to § 30.2095(1)(b) to prevent a permit from becoming void under § 30.2095(1)(a). The DNR possesses a limited right to modify a permit until the earlier of the expiration date of the permit or the date when pier placement was completed, as set forth in § 30.2095(2). However, that right does not include the *193ability to require partial removal of a pier, and substantial modification to a permit, over 14 years after a pier was placed.12
¶ 33 A review of the language used in ch. 30 further supports the conclusion that a pier permit is akin to a building permit and includes no additional requirements for ongoing maintenance and use. As previously noted, "[s]tatutory language is interpreted in the context in which it is used; not in isolation but as part of a whole; in relation to the language of surrounding or closely-related statutes; and reasonably, to avoid absurd or unreasonable results." Kalal, 271 Wis. 2d 633, ¶ 45, 681 N.W.2d 110. Pier permits are described throughout ch. 30 in reference to the "placement" of a structure. See, e.g., Wis. Stat. § 30.12(1)(a) (providing that a permit is required to "place any structure upon the bed of any navigable water"); § 30.12(3m)(a) (providing that a permit is required "in order to place the structure for the owner's use"). The Merriam Webster Dictionary defines place as "to put in or as if in a particular place or position: set." "Place," Merriam Webster Online Dictionary (2018), https://www.merriam-webster.com/dictionary/place. Therefore, "[p]lacement" refers to setting a pier in the navigable waters, not the ongoing use of a pier.
¶ 34 Where the legislature intends to include the responsibility of ongoing maintenance, it specifies as such, as seen in Wis. Stat. § 30.131, which regulates piers "placed and maintained by persons other than riparian owners." If "placed" was synonymous with *194"maintained," the word "maintained" in § 30.131 would be surplusage. Additionally, in enacting regulations for a permit for a dam, the legislature clarified that the permit also includes ongoing maintenance. See, e.g., Wis. Stat. § 31.05 (describing the permit as one "to *56construct, operate and maintain a dam"). We look to the words chosen by the legislature in the context of the entirety of Wis. Stat. ch. 30 and conclude that the Myers' pier permit was akin to a building permit.
¶ 35 Because we conclude that the DNR lacked authority to amend the Myers' permit, we need not reach the issues that surround the application of the statutory exemptions in Wis. Stat. § 30.12(1k), including the court of appeals' reliance on "implicit findings" made by the DNR at a public informational hearing.
IV. CONCLUSION
¶ 36 On petition to this court, the Myers sought review of the DNR's authority to amend their 2001 pier permit. The Myers also sought review as to whether two exemptions in Wis. Stat. § 30.12(1k) barred the DNR's actions. Lastly, the Myers sought review of whether the court of appeals could rely on "implicit findings" made by the DNR at a public informational hearing to conclude that the statutory exemptions in § 30.12(1k) did not apply to the Myers' pier.
¶ 37 We conclude that the DNR could not reserve to itself the authority to amend the Myers' permit through Condition 1. We conclude that Wis. Stat. § 30.12(3m)(d)2. did not provide the DNR with statutory authorization to insert Condition 1 in the Myers' permit. Further, we conclude that because the Myers' permit expired, Wis. Stat. § 30.2095 did not *195provide the DNR with the authority to modify or rescind the Myers' permit for "good cause." Because the DNR had no authority to amend the Myers' permit and we reverse the court of appeals' decision, we need not address whether the statutory exemptions found in § 30.12(1k) applied to the Myers' pier.
By the Court. -The decision of the court of appeals is reversed.
A. W. Bradley, J. dissents (opinion filed).