delivered the opinion of the court.
The purpose of this action, brought by appellants as plaintiffs, was to annul assessments levied against their property to defray the expense of the construction of what is known as the Capitol Hill Storm Sewer and sub-sewers in the 'city of Denver. From a judgment denying them this relief, they bring the ease here on appeal. The numerous questions argued by their counsel, for convenience, will be considered under the following heads:
1. The constitutionality of the charter provi*174sions relating to tlie board of public works and the procedure provided.
2. The exemption of property in the district.
3. Irregularities in assessments.
4. The question of benefits to the property assessed.
5. "Whether the sewer was a local or general public improvement.
6. Irregularities on the part of the city authorities.
1. All the propositions urged by counsel in support of their contention that the charter -provisions respecting the authority of the board of public works and the provisions respecting the procedure, in so far as the latter relates to what may be termed ‘ ‘ due process of law,” have been considered and determined adversely to the claim of counsel in the preceding cases of City of Denver v. Londoner, ante, p. 104; City of Denver v. Dumars, ante, p. 94; and City of Denver v. Kennedy, ante, p. 80.
It is claimed that the provisions of the charter, section 23, article 7 (section 180), to the effect that the construction of storm sewers shall not be the subject of petition or remonstrance, is in violation of both the state and federal constitutions. It will be noted, from an examination of other provisions of the charter, that the board of public works cannot initiate certain public improvements except on the petition of the. property owners, and that, in some instances, a remonstrance filed in apt time deprives the board of all authority to further proceed. It was the purpose of section 23, supra, to vest the city authorities with the power to initiate the construction of storm sewers without the action of the owners of property of the district in which the sewer was constructed. There is no valid objection to such a provision. In the absence of statutory provisions, the *175city authorities may initiate and complete public improvements without preliminary action on the part of the owners whose property may he assessed for the expense of such improvement. A law to this effect, does not deprive the owners of any fundamental right. — City of Denver v. Londoner, supra.
2. In making the assessments, the city authorities exempted certain parks and various triangular tracts of land along Park Avenue. No assessment Avas made on the interests of the street railway company in the street car tracks laid on and along certain streets in the district. It appears from the notice which the city clerk is required to give, by virtue of section 30, article 7 (section 187), charter, that the property excepted was not to be assessed with any part of the expense of the construction of the sewer. No protests were made by plaintiffs against these exceptions, nor did they file any complaints or objections in response to the notice given by the clerk. No doubt, in the preliminary stages of the creation of a sewer district, the question of exemptions of property therein from bearing its legal proportion of the expense of a local public improvement could be heard and determined, but owners injuriously affected by such exemptions must move in apt time. They will not be permitted to remain silent touching the matters of which they have notice, and then, for the first time, after the improvement has been completed and the assessment made upon their property, claim that the assessment is void because of matters which might haAm been corrected had they interposed their objection before the expense of construction was incurred. The omission of property from bearing its proportion of a special assessment does not render the entire assessment Aroid. The most that plaintiffs could claim would be that an unjust burden was imposed upon their property because of the exemp*176tions of other property in the district benefited by the sewer. The law has provided a forum, namely, the city council sitting as a board of equalization, to determine the question of assessments and apportionments. The plaintiffs have not seen fit to avail themselves of the opportunity thus afforded to have their assessments reduced, if, under the law and facts, they would have been entitled to such a reduction, and therefore cannot appeal to a court of equity for the relief which they might have obtained in the special forum the law has provided. — City of Denver v. Dumars, supra.
3. Under the third proposition, designated “irregularities in assessments,” the claims that the assessing ordinance should have assessed separately each tract of land with its proportion of the cost; that the city auditor was without authority to compute, as he did, the assessment against each lot; that he. unlawfully added interest on the assessments; and that the assessing ordinance prematurely declared the entire assessment due and payable — will be considered. The assessing ordinance describes the boundaries of the district, states the property exempted, designates the total sum of the assessment, and recites the amount assessed against each lot of a given size, and the rate per square foot for other tracts in the district. There is no provision of law which requires the assessing ordinance to recite the specific amount with which each lot is charged. On the contrary, general section 218 of the charter expressly provides that it is not necessary to designate in the assessing ordinance - each piece of real estate in the district separately, but that general descriptions are'sufficient, and the assessment may be stated as being so much per square foot or per lot of a given size. To enter into details by describing each lot separately in the assessing ordinance and *177designating the amount assessed against each tract would necessitate a long and cumbersome ordinance, without any benefit. It is the function of the city council to determine the rate of assessment against property in a given district, and then it devolves upon other city authorities to carry out the details. This is fully provided for in section 33, article 7 (section 190), charter, which provides that the city auditor shall prepare a local assessment roll, showing, in suitable columns, all the details necessary to acquaint each owner with the amount of the assessment against his property. All this information he obtains from the assessing ordinance, and the matter of separate description and amount to be assessed against each lot is Only a question of detail.
If, as claimed, the auditor unlawfully added interest to the assessments, or the ordinance prematurely declared the entire assessment due and payable, they are not matters which can be considered or determined in this action. Plaintiffs must first tender to the proper authorities the amount of principal which they claim is all they owe, and offer to pay the sum which, according to their contention, is correct, before either of these questions can be presented to a court for adjudication.
4. It is contended that the assessments complained of were levied without regard to the question of benefits; that the natural slope of the land within the sewer district was sufficient to drain it, and that property outside of the storm sewer district was benefited and not assessed. Testimony on these questions was received by the trial court. It is not necessary, however, to examine this evidence or attempt to determine what it may establish on these questions. We have decided that the rule ’ of apportionment according to area is prima facie valid. — City of Denver v. Dumars, supra; but that where any general *178method employed, though prima facie valid, would work an injustice, relief, in proper circumstances, may be granted. — City of Denver v. Londoner, supra. Before parties aggrieved by an assessment levied undel' a fixed rule which appears to be reasonable and likely to proximate an equality of assessments, can appeal to a court of equity to relieve them from an alleged excess, or because their property was not, in fact, benefited, they must at least first apply for such relief to the special tribunal which the law has provided to settle these questions. The plaintiffs never attempted to raise any of these questions before the city authorities, and are, therefore, not in a position to litigate them in a court of equity. — City of Denver v. Dumars, supra.
5. Appellants contend that the sewer is a public improvement of such a character that the cost should have been assessed against the city, instead of a district. This only raises the question of special benefits in another way. The_ failure of appellants to file complaints or objections to the proposed assessments for the consideration of the special forum provided b3r law to determine the question of special benefits, precluded them from resorting to a court of equity for relief in the first instance.
6. Certain irregularities on the part of the board of public works were alleged and shown. These alleged irregularities may have affected the validity of the contract, had they been raised at the proper time. If the city authorities were not following the law in letting- contracts, they could doubtless have been required to do so by an appropriate action in apt time, but after the contracts have been completed, it is too late to raise questions of this, kind in an attack upon the validity of the assessment.
The judgment of the district court will stand affirmed. Judgment affirmed.